LibJS+Everywhere: Allow Cell::initialize overrides to throw OOM errors

Note that as of this commit, there aren't any such throwers, and the
call site in Heap::allocate will drop exceptions on the floor. This
commit only serves to change the declaration of the overrides, make sure
they return an empty value, and to propagate OOM errors frm their base
initialize invocations.

Userland/Libraries/LibJS/Runtime/Intl/CollatorCompareFunction.cpp

@@ -22,11 +22,13 @@ CollatorCompareFunction::CollatorCompareFunction(Realm& realm, Collator& collato
 {
 }
 
-void CollatorCompareFunction::initialize(Realm&)
+ThrowCompletionOr<void> CollatorCompareFunction::initialize(Realm&)
 {
     auto& vm = this->vm();
     define_direct_property(vm.names.length, Value(2), Attribute::Configurable);
     define_direct_property(vm.names.name, PrimitiveString::create(vm, String {}), Attribute::Configurable);
+
+    return {};
 }
 
 // 10.3.3.2 CompareStrings ( collator, x, y ), https://tc39.es/ecma402/#sec-collator-comparestrings

Userland/Libraries/LibJS/Runtime/Intl/CollatorCompareFunction.h

@@ -16,7 +16,7 @@ class CollatorCompareFunction : public NativeFunction {
 public:
     static NonnullGCPtr<CollatorCompareFunction> create(Realm&, Collator&);
 
-    virtual void initialize(Realm&) override;
+    virtual ThrowCompletionOr<void> initialize(Realm&) override;
     virtual ~CollatorCompareFunction() override = default;
 
     virtual ThrowCompletionOr<Value> call() override;

Userland/Libraries/LibJS/Runtime/Intl/CollatorConstructor.cpp

@@ -135,9 +135,9 @@ CollatorConstructor::CollatorConstructor(Realm& realm)
 {
 }
 
-void CollatorConstructor::initialize(Realm& realm)
+ThrowCompletionOr<void> CollatorConstructor::initialize(Realm& realm)
 {
-    NativeFunction::initialize(realm);
+    MUST_OR_THROW_OOM(NativeFunction::initialize(realm));
 
     auto& vm = this->vm();
 
@@ -147,6 +147,8 @@ void CollatorConstructor::initialize(Realm& realm)
 
     u8 attr = Attribute::Writable | Attribute::Configurable;
     define_native_function(realm, vm.names.supportedLocalesOf, supported_locales_of, 1, attr);
+
+    return {};
 }
 
 // 10.1.1 Intl.Collator ( [ locales [ , options ] ] ), https://tc39.es/ecma402/#sec-intl.collator

Userland/Libraries/LibJS/Runtime/Intl/CollatorConstructor.h

@@ -14,7 +14,7 @@ class CollatorConstructor final : public NativeFunction {
     JS_OBJECT(CollatorConstructor, NativeFunction);
 
 public:
-    virtual void initialize(Realm&) override;
+    virtual ThrowCompletionOr<void> initialize(Realm&) override;
     virtual ~CollatorConstructor() override = default;
 
     virtual ThrowCompletionOr<Value> call() override;

Userland/Libraries/LibJS/Runtime/Intl/CollatorPrototype.cpp

@@ -17,9 +17,9 @@ CollatorPrototype::CollatorPrototype(Realm& realm)
 {
 }
 
-void CollatorPrototype::initialize(Realm& realm)
+ThrowCompletionOr<void> CollatorPrototype::initialize(Realm& realm)
 {
-    Object::initialize(realm);
+    MUST_OR_THROW_OOM(Object::initialize(realm));
 
     auto& vm = this->vm();
 
@@ -29,6 +29,8 @@ void CollatorPrototype::initialize(Realm& realm)
     u8 attr = Attribute::Writable | Attribute::Configurable;
     define_native_accessor(realm, vm.names.compare, compare_getter, {}, attr);
     define_native_function(realm, vm.names.resolvedOptions, resolved_options, 0, attr);
+
+    return {};
 }
 
 // 10.3.3 get Intl.Collator.prototype.compare, https://tc39.es/ecma402/#sec-intl.collator.prototype.compare

Userland/Libraries/LibJS/Runtime/Intl/CollatorPrototype.h

@@ -15,7 +15,7 @@ class CollatorPrototype final : public PrototypeObject<CollatorPrototype, Collat
     JS_PROTOTYPE_OBJECT(CollatorPrototype, Collator, Collator);
 
 public:
-    virtual void initialize(Realm&) override;
+    virtual ThrowCompletionOr<void> initialize(Realm&) override;
     virtual ~CollatorPrototype() override = default;
 
 private:

Userland/Libraries/LibJS/Runtime/Intl/DateTimeFormatConstructor.cpp

@@ -23,9 +23,9 @@ DateTimeFormatConstructor::DateTimeFormatConstructor(Realm& realm)
 {
 }
 
-void DateTimeFormatConstructor::initialize(Realm& realm)
+ThrowCompletionOr<void> DateTimeFormatConstructor::initialize(Realm& realm)
 {
-    NativeFunction::initialize(realm);
+    MUST_OR_THROW_OOM(NativeFunction::initialize(realm));
 
     auto& vm = this->vm();
 
@@ -36,6 +36,8 @@ void DateTimeFormatConstructor::initialize(Realm& realm)
     define_native_function(realm, vm.names.supportedLocalesOf, supported_locales_of, 1, attr);
 
     define_direct_property(vm.names.length, Value(0), Attribute::Configurable);
+
+    return {};
 }
 
 // 11.1.1 Intl.DateTimeFormat ( [ locales [ , options ] ] ), https://tc39.es/ecma402/#sec-intl.datetimeformat

Userland/Libraries/LibJS/Runtime/Intl/DateTimeFormatConstructor.h

@@ -14,7 +14,7 @@ class DateTimeFormatConstructor final : public NativeFunction {
     JS_OBJECT(DateTimeFormatConstructor, NativeFunction);
 
 public:
-    virtual void initialize(Realm&) override;
+    virtual ThrowCompletionOr<void> initialize(Realm&) override;
     virtual ~DateTimeFormatConstructor() override = default;
 
     virtual ThrowCompletionOr<Value> call() override;

Userland/Libraries/LibJS/Runtime/Intl/DateTimeFormatFunction.cpp

@@ -25,13 +25,15 @@ DateTimeFormatFunction::DateTimeFormatFunction(DateTimeFormat& date_time_format,
 {
 }
 
-void DateTimeFormatFunction::initialize(Realm& realm)
+ThrowCompletionOr<void> DateTimeFormatFunction::initialize(Realm& realm)
 {
     auto& vm = this->vm();
 
-    Base::initialize(realm);
+    MUST_OR_THROW_OOM(Base::initialize(realm));
     define_direct_property(vm.names.length, Value(1), Attribute::Configurable);
     define_direct_property(vm.names.name, PrimitiveString::create(vm, String {}), Attribute::Configurable);
+
+    return {};
 }
 
 ThrowCompletionOr<Value> DateTimeFormatFunction::call()

Userland/Libraries/LibJS/Runtime/Intl/DateTimeFormatFunction.h

@@ -19,7 +19,7 @@ public:
     static NonnullGCPtr<DateTimeFormatFunction> create(Realm&, DateTimeFormat&);
 
     virtual ~DateTimeFormatFunction() override = default;
-    virtual void initialize(Realm&) override;
+    virtual ThrowCompletionOr<void> initialize(Realm&) override;
 
     virtual ThrowCompletionOr<Value> call() override;
 

Userland/Libraries/LibJS/Runtime/Intl/DateTimeFormatPrototype.cpp

@@ -19,9 +19,9 @@ DateTimeFormatPrototype::DateTimeFormatPrototype(Realm& realm)
 {
 }
 
-void DateTimeFormatPrototype::initialize(Realm& realm)
+ThrowCompletionOr<void> DateTimeFormatPrototype::initialize(Realm& realm)
 {
-    Object::initialize(realm);
+    MUST_OR_THROW_OOM(Base::initialize(realm));
 
     auto& vm = this->vm();
 
@@ -35,6 +35,8 @@ void DateTimeFormatPrototype::initialize(Realm& realm)
     define_native_function(realm, vm.names.formatRange, format_range, 2, attr);
     define_native_function(realm, vm.names.formatRangeToParts, format_range_to_parts, 2, attr);
     define_native_function(realm, vm.names.resolvedOptions, resolved_options, 0, attr);
+
+    return {};
 }
 
 // 11.3.3 get Intl.DateTimeFormat.prototype.format, https://tc39.es/ecma402/#sec-intl.datetimeformat.prototype.format

Userland/Libraries/LibJS/Runtime/Intl/DateTimeFormatPrototype.h

@@ -15,7 +15,7 @@ class DateTimeFormatPrototype final : public PrototypeObject<DateTimeFormatProto
     JS_PROTOTYPE_OBJECT(DateTimeFormatPrototype, DateTimeFormat, Intl.DateTimeFormat);
 
 public:
-    virtual void initialize(Realm&) override;
+    virtual ThrowCompletionOr<void> initialize(Realm&) override;
     virtual ~DateTimeFormatPrototype() override = default;
 
 private:

Userland/Libraries/LibJS/Runtime/Intl/DisplayNamesConstructor.cpp

@@ -21,9 +21,9 @@ DisplayNamesConstructor::DisplayNamesConstructor(Realm& realm)
 {
 }
 
-void DisplayNamesConstructor::initialize(Realm& realm)
+ThrowCompletionOr<void> DisplayNamesConstructor::initialize(Realm& realm)
 {
-    NativeFunction::initialize(realm);
+    MUST_OR_THROW_OOM(NativeFunction::initialize(realm));
 
     auto& vm = this->vm();
 
@@ -34,6 +34,8 @@ void DisplayNamesConstructor::initialize(Realm& realm)
     define_native_function(realm, vm.names.supportedLocalesOf, supported_locales_of, 1, attr);
 
     define_direct_property(vm.names.length, Value(2), Attribute::Configurable);
+
+    return {};
 }
 
 // 12.1.1 Intl.DisplayNames ( locales, options ), https://tc39.es/ecma402/#sec-Intl.DisplayNames

Userland/Libraries/LibJS/Runtime/Intl/DisplayNamesConstructor.h

@@ -14,7 +14,7 @@ class DisplayNamesConstructor final : public NativeFunction {
     JS_OBJECT(DisplayNamesConstructor, NativeFunction);
 
 public:
-    virtual void initialize(Realm&) override;
+    virtual ThrowCompletionOr<void> initialize(Realm&) override;
     virtual ~DisplayNamesConstructor() override = default;
 
     virtual ThrowCompletionOr<Value> call() override;

Userland/Libraries/LibJS/Runtime/Intl/DisplayNamesPrototype.cpp

@@ -19,9 +19,9 @@ DisplayNamesPrototype::DisplayNamesPrototype(Realm& realm)
 {
 }
 
-void DisplayNamesPrototype::initialize(Realm& realm)
+ThrowCompletionOr<void> DisplayNamesPrototype::initialize(Realm& realm)
 {
-    Object::initialize(realm);
+    MUST_OR_THROW_OOM(Base::initialize(realm));
 
     auto& vm = this->vm();
 
@@ -31,6 +31,8 @@ void DisplayNamesPrototype::initialize(Realm& realm)
     u8 attr = Attribute::Writable | Attribute::Configurable;
     define_native_function(realm, vm.names.of, of, 1, attr);
     define_native_function(realm, vm.names.resolvedOptions, resolved_options, 0, attr);
+
+    return {};
 }
 
 // 12.3.3 Intl.DisplayNames.prototype.of ( code ), https://tc39.es/ecma402/#sec-Intl.DisplayNames.prototype.of

Userland/Libraries/LibJS/Runtime/Intl/DisplayNamesPrototype.h

@@ -15,7 +15,7 @@ class DisplayNamesPrototype final : public PrototypeObject<DisplayNamesPrototype
     JS_PROTOTYPE_OBJECT(DisplayNamesPrototype, DisplayNames, Intl.DisplayNames);
 
 public:
-    virtual void initialize(Realm&) override;
+    virtual ThrowCompletionOr<void> initialize(Realm&) override;
     virtual ~DisplayNamesPrototype() override = default;
 
 private:

Userland/Libraries/LibJS/Runtime/Intl/DurationFormatConstructor.cpp

@@ -20,9 +20,9 @@ DurationFormatConstructor::DurationFormatConstructor(Realm& realm)
 {
 }
 
-void DurationFormatConstructor::initialize(Realm& realm)
+ThrowCompletionOr<void> DurationFormatConstructor::initialize(Realm& realm)
 {
-    NativeFunction::initialize(realm);
+    MUST_OR_THROW_OOM(NativeFunction::initialize(realm));
 
     auto& vm = this->vm();
 
@@ -32,6 +32,8 @@ void DurationFormatConstructor::initialize(Realm& realm)
 
     u8 attr = Attribute::Writable | Attribute::Configurable;
     define_native_function(realm, vm.names.supportedLocalesOf, supported_locales_of, 1, attr);
+
+    return {};
 }
 
 // 1.2.1 Intl.DurationFormat ( [ locales [ , options ] ] ), https://tc39.es/proposal-intl-duration-format/#sec-Intl.DurationFormat

Userland/Libraries/LibJS/Runtime/Intl/DurationFormatConstructor.h

@@ -14,7 +14,7 @@ class DurationFormatConstructor final : public NativeFunction {
     JS_OBJECT(DurationFormatConstructor, NativeFunction);
 
 public:
-    virtual void initialize(Realm&) override;
+    virtual ThrowCompletionOr<void> initialize(Realm&) override;
     virtual ~DurationFormatConstructor() override = default;
 
     virtual ThrowCompletionOr<Value> call() override;

Userland/Libraries/LibJS/Runtime/Intl/DurationFormatPrototype.cpp

@@ -18,9 +18,9 @@ DurationFormatPrototype::DurationFormatPrototype(Realm& realm)
 {
 }
 
-void DurationFormatPrototype::initialize(Realm& realm)
+ThrowCompletionOr<void> DurationFormatPrototype::initialize(Realm& realm)
 {
-    Object::initialize(realm);
+    MUST_OR_THROW_OOM(Base::initialize(realm));
 
     auto& vm = this->vm();
 
@@ -31,6 +31,8 @@ void DurationFormatPrototype::initialize(Realm& realm)
     define_native_function(realm, vm.names.format, format, 1, attr);
     define_native_function(realm, vm.names.formatToParts, format_to_parts, 1, attr);
     define_native_function(realm, vm.names.resolvedOptions, resolved_options, 0, attr);
+
+    return {};
 }
 
 // 1.4.3 Intl.DurationFormat.prototype.format ( duration ), https://tc39.es/proposal-intl-duration-format/#sec-Intl.DurationFormat.prototype.format

Userland/Libraries/LibJS/Runtime/Intl/DurationFormatPrototype.h

@@ -15,7 +15,7 @@ class DurationFormatPrototype final : public PrototypeObject<DurationFormatProto
     JS_PROTOTYPE_OBJECT(DurationFormatPrototype, DurationFormat, Intl.DurationFormat);
 
 public:
-    virtual void initialize(Realm&) override;
+    virtual ThrowCompletionOr<void> initialize(Realm&) override;
     virtual ~DurationFormatPrototype() override = default;
 
 private:

Userland/Libraries/LibJS/Runtime/Intl/Intl.cpp

@@ -32,9 +32,9 @@ Intl::Intl(Realm& realm)
 {
 }
 
-void Intl::initialize(Realm& realm)
+ThrowCompletionOr<void> Intl::initialize(Realm& realm)
 {
-    Object::initialize(realm);
+    MUST_OR_THROW_OOM(Object::initialize(realm));
 
     auto& vm = this->vm();
 
@@ -55,6 +55,8 @@ void Intl::initialize(Realm& realm)
 
     define_native_function(realm, vm.names.getCanonicalLocales, get_canonical_locales, 1, attr);
     define_native_function(realm, vm.names.supportedValuesOf, supported_values_of, 1, attr);
+
+    return {};
 }
 
 // 8.3.1 Intl.getCanonicalLocales ( locales ), https://tc39.es/ecma402/#sec-intl.getcanonicallocales

Userland/Libraries/LibJS/Runtime/Intl/Intl.h

@@ -14,7 +14,7 @@ class Intl final : public Object {
     JS_OBJECT(Intl, Object);
 
 public:
-    virtual void initialize(Realm&) override;
+    virtual ThrowCompletionOr<void> initialize(Realm&) override;
     virtual ~Intl() override = default;
 
 private:

Userland/Libraries/LibJS/Runtime/Intl/ListFormatConstructor.cpp

@@ -20,9 +20,9 @@ ListFormatConstructor::ListFormatConstructor(Realm& realm)
 {
 }
 
-void ListFormatConstructor::initialize(Realm& realm)
+ThrowCompletionOr<void> ListFormatConstructor::initialize(Realm& realm)
 {
-    NativeFunction::initialize(realm);
+    MUST_OR_THROW_OOM(NativeFunction::initialize(realm));
 
     auto& vm = this->vm();
 
@@ -33,6 +33,8 @@ void ListFormatConstructor::initialize(Realm& realm)
     define_native_function(realm, vm.names.supportedLocalesOf, supported_locales_of, 1, attr);
 
     define_direct_property(vm.names.length, Value(0), Attribute::Configurable);
+
+    return {};
 }
 
 // 13.1.1 Intl.ListFormat ( [ locales [ , options ] ] ), https://tc39.es/ecma402/#sec-Intl.ListFormat

Userland/Libraries/LibJS/Runtime/Intl/ListFormatConstructor.h

@@ -14,7 +14,7 @@ class ListFormatConstructor final : public NativeFunction {
     JS_OBJECT(ListFormatConstructor, NativeFunction);
 
 public:
-    virtual void initialize(Realm&) override;
+    virtual ThrowCompletionOr<void> initialize(Realm&) override;
     virtual ~ListFormatConstructor() override = default;
 
     virtual ThrowCompletionOr<Value> call() override;

Userland/Libraries/LibJS/Runtime/Intl/ListFormatPrototype.cpp

@@ -18,9 +18,9 @@ ListFormatPrototype::ListFormatPrototype(Realm& realm)
 {
 }
 
-void ListFormatPrototype::initialize(Realm& realm)
+ThrowCompletionOr<void> ListFormatPrototype::initialize(Realm& realm)
 {
-    Object::initialize(realm);
+    MUST_OR_THROW_OOM(Base::initialize(realm));
 
     auto& vm = this->vm();
 
@@ -31,6 +31,8 @@ void ListFormatPrototype::initialize(Realm& realm)
     define_native_function(realm, vm.names.format, format, 1, attr);
     define_native_function(realm, vm.names.formatToParts, format_to_parts, 1, attr);
     define_native_function(realm, vm.names.resolvedOptions, resolved_options, 0, attr);
+
+    return {};
 }
 
 // 13.3.3 Intl.ListFormat.prototype.format ( list ), https://tc39.es/ecma402/#sec-Intl.ListFormat.prototype.format

Userland/Libraries/LibJS/Runtime/Intl/ListFormatPrototype.h

@@ -15,7 +15,7 @@ class ListFormatPrototype final : public PrototypeObject<ListFormatPrototype, Li
     JS_PROTOTYPE_OBJECT(ListFormatPrototype, ListFormat, Intl.ListFormat);
 
 public:
-    virtual void initialize(Realm&) override;
+    virtual ThrowCompletionOr<void> initialize(Realm&) override;
     virtual ~ListFormatPrototype() override = default;
 
 private:

Userland/Libraries/LibJS/Runtime/Intl/LocaleConstructor.cpp

@@ -222,15 +222,17 @@ LocaleConstructor::LocaleConstructor(Realm& realm)
 {
 }
 
-void LocaleConstructor::initialize(Realm& realm)
+ThrowCompletionOr<void> LocaleConstructor::initialize(Realm& realm)
 {
-    NativeFunction::initialize(realm);
+    MUST_OR_THROW_OOM(NativeFunction::initialize(realm));
 
     auto& vm = this->vm();
 
     // 14.2.1 Intl.Locale.prototype, https://tc39.es/ecma402/#sec-Intl.Locale.prototype
     define_direct_property(vm.names.prototype, realm.intrinsics().intl_locale_prototype(), 0);
     define_direct_property(vm.names.length, Value(1), Attribute::Configurable);
+
+    return {};
 }
 
 // 14.1.1 Intl.Locale ( tag [ , options ] ), https://tc39.es/ecma402/#sec-Intl.Locale

Userland/Libraries/LibJS/Runtime/Intl/LocaleConstructor.h

@@ -14,7 +14,7 @@ class LocaleConstructor final : public NativeFunction {
     JS_OBJECT(LocaleConstructor, NativeFunction);
 
 public:
-    virtual void initialize(Realm&) override;
+    virtual ThrowCompletionOr<void> initialize(Realm&) override;
     virtual ~LocaleConstructor() override = default;
 
     virtual ThrowCompletionOr<Value> call() override;

Userland/Libraries/LibJS/Runtime/Intl/LocalePrototype.cpp

@@ -19,9 +19,9 @@ LocalePrototype::LocalePrototype(Realm& realm)
 {
 }
 
-void LocalePrototype::initialize(Realm& realm)
+ThrowCompletionOr<void> LocalePrototype::initialize(Realm& realm)
 {
-    Object::initialize(realm);
+    MUST_OR_THROW_OOM(Base::initialize(realm));
 
     auto& vm = this->vm();
 
@@ -50,6 +50,8 @@ void LocalePrototype::initialize(Realm& realm)
     define_native_accessor(realm, vm.names.timeZones, time_zones, {}, Attribute::Configurable);
     define_native_accessor(realm, vm.names.textInfo, text_info, {}, Attribute::Configurable);
     define_native_accessor(realm, vm.names.weekInfo, week_info, {}, Attribute::Configurable);
+
+    return {};
 }
 
 // 14.3.3 Intl.Locale.prototype.maximize ( ), https://tc39.es/ecma402/#sec-Intl.Locale.prototype.maximize

Userland/Libraries/LibJS/Runtime/Intl/LocalePrototype.h

@@ -15,7 +15,7 @@ class LocalePrototype final : public PrototypeObject<LocalePrototype, Locale> {
     JS_PROTOTYPE_OBJECT(LocalePrototype, Locale, Intl.Locale);
 
 public:
-    virtual void initialize(Realm&) override;
+    virtual ThrowCompletionOr<void> initialize(Realm&) override;
     virtual ~LocalePrototype() override = default;
 
 private:

Userland/Libraries/LibJS/Runtime/Intl/NumberFormatConstructor.cpp

@@ -19,9 +19,9 @@ NumberFormatConstructor::NumberFormatConstructor(Realm& realm)
 {
 }
 
-void NumberFormatConstructor::initialize(Realm& realm)
+ThrowCompletionOr<void> NumberFormatConstructor::initialize(Realm& realm)
 {
-    NativeFunction::initialize(realm);
+    MUST_OR_THROW_OOM(NativeFunction::initialize(realm));
 
     auto& vm = this->vm();
 
@@ -32,6 +32,8 @@ void NumberFormatConstructor::initialize(Realm& realm)
     define_native_function(realm, vm.names.supportedLocalesOf, supported_locales_of, 1, attr);
 
     define_direct_property(vm.names.length, Value(0), Attribute::Configurable);
+
+    return {};
 }
 
 // 15.1.1 Intl.NumberFormat ( [ locales [ , options ] ] ), https://tc39.es/ecma402/#sec-intl.numberformat

Userland/Libraries/LibJS/Runtime/Intl/NumberFormatConstructor.h

@@ -15,7 +15,7 @@ class NumberFormatConstructor final : public NativeFunction {
     JS_OBJECT(NumberFormatConstructor, NativeFunction);
 
 public:
-    virtual void initialize(Realm&) override;
+    virtual ThrowCompletionOr<void> initialize(Realm&) override;
     virtual ~NumberFormatConstructor() override = default;
 
     virtual ThrowCompletionOr<Value> call() override;

Userland/Libraries/LibJS/Runtime/Intl/NumberFormatFunction.cpp

@@ -23,13 +23,15 @@ NumberFormatFunction::NumberFormatFunction(NumberFormat& number_format, Object&
 {
 }
 
-void NumberFormatFunction::initialize(Realm& realm)
+ThrowCompletionOr<void> NumberFormatFunction::initialize(Realm& realm)
 {
     auto& vm = this->vm();
 
-    Base::initialize(realm);
+    MUST_OR_THROW_OOM(Base::initialize(realm));
     define_direct_property(vm.names.length, Value(1), Attribute::Configurable);
     define_direct_property(vm.names.name, PrimitiveString::create(vm, String {}), Attribute::Configurable);
+
+    return {};
 }
 
 ThrowCompletionOr<Value> NumberFormatFunction::call()

Userland/Libraries/LibJS/Runtime/Intl/NumberFormatFunction.h

@@ -19,7 +19,7 @@ public:
     static NonnullGCPtr<NumberFormatFunction> create(Realm&, NumberFormat&);
 
     virtual ~NumberFormatFunction() override = default;
-    virtual void initialize(Realm&) override;
+    virtual ThrowCompletionOr<void> initialize(Realm&) override;
 
     virtual ThrowCompletionOr<Value> call() override;
 

Userland/Libraries/LibJS/Runtime/Intl/NumberFormatPrototype.cpp

@@ -19,9 +19,9 @@ NumberFormatPrototype::NumberFormatPrototype(Realm& realm)
 {
 }
 
-void NumberFormatPrototype::initialize(Realm& realm)
+ThrowCompletionOr<void> NumberFormatPrototype::initialize(Realm& realm)
 {
-    Object::initialize(realm);
+    MUST_OR_THROW_OOM(Base::initialize(realm));
 
     auto& vm = this->vm();
 
@@ -35,6 +35,8 @@ void NumberFormatPrototype::initialize(Realm& realm)
     define_native_function(realm, vm.names.formatRange, format_range, 2, attr);
     define_native_function(realm, vm.names.formatRangeToParts, format_range_to_parts, 2, attr);
     define_native_function(realm, vm.names.resolvedOptions, resolved_options, 0, attr);
+
+    return {};
 }
 
 // 15.3.3 get Intl.NumberFormat.prototype.format, https://tc39.es/ecma402/#sec-intl.numberformat.prototype.format

Userland/Libraries/LibJS/Runtime/Intl/NumberFormatPrototype.h

@@ -15,7 +15,7 @@ class NumberFormatPrototype final : public PrototypeObject<NumberFormatPrototype
     JS_PROTOTYPE_OBJECT(NumberFormatPrototype, NumberFormat, Intl.NumberFormat);
 
 public:
-    virtual void initialize(Realm&) override;
+    virtual ThrowCompletionOr<void> initialize(Realm&) override;
     virtual ~NumberFormatPrototype() override = default;
 
 private:

Userland/Libraries/LibJS/Runtime/Intl/PluralRulesConstructor.cpp

@@ -21,9 +21,9 @@ PluralRulesConstructor::PluralRulesConstructor(Realm& realm)
 {
 }
 
-void PluralRulesConstructor::initialize(Realm& realm)
+ThrowCompletionOr<void> PluralRulesConstructor::initialize(Realm& realm)
 {
-    NativeFunction::initialize(realm);
+    MUST_OR_THROW_OOM(NativeFunction::initialize(realm));
 
     auto& vm = this->vm();
 
@@ -33,6 +33,8 @@ void PluralRulesConstructor::initialize(Realm& realm)
 
     u8 attr = Attribute::Writable | Attribute::Configurable;
     define_native_function(realm, vm.names.supportedLocalesOf, supported_locales_of, 1, attr);
+
+    return {};
 }
 
 // 16.1.1 Intl.PluralRules ( [ locales [ , options ] ] ), https://tc39.es/ecma402/#sec-intl.pluralrules

Userland/Libraries/LibJS/Runtime/Intl/PluralRulesConstructor.h

@@ -14,7 +14,7 @@ class PluralRulesConstructor final : public NativeFunction {
     JS_OBJECT(PluralRulesConstructor, NativeFunction);
 
 public:
-    virtual void initialize(Realm&) override;
+    virtual ThrowCompletionOr<void> initialize(Realm&) override;
     virtual ~PluralRulesConstructor() override = default;
 
     virtual ThrowCompletionOr<Value> call() override;

Userland/Libraries/LibJS/Runtime/Intl/PluralRulesPrototype.cpp

@@ -18,9 +18,9 @@ PluralRulesPrototype::PluralRulesPrototype(Realm& realm)
 {
 }
 
-void PluralRulesPrototype::initialize(Realm& realm)
+ThrowCompletionOr<void> PluralRulesPrototype::initialize(Realm& realm)
 {
-    Object::initialize(realm);
+    MUST_OR_THROW_OOM(Object::initialize(realm));
 
     auto& vm = this->vm();
 
@@ -31,6 +31,8 @@ void PluralRulesPrototype::initialize(Realm& realm)
     define_native_function(realm, vm.names.select, select, 1, attr);
     define_native_function(realm, vm.names.selectRange, select_range, 2, attr);
     define_native_function(realm, vm.names.resolvedOptions, resolved_options, 0, attr);
+
+    return {};
 }
 
 // 16.3.3 Intl.PluralRules.prototype.select ( value ), https://tc39.es/ecma402/#sec-intl.pluralrules.prototype.select

Userland/Libraries/LibJS/Runtime/Intl/PluralRulesPrototype.h

@@ -15,7 +15,7 @@ class PluralRulesPrototype final : public PrototypeObject<PluralRulesPrototype,
     JS_PROTOTYPE_OBJECT(PluralRulesPrototype, PluralRules, Intl.PluralRules);
 
 public:
-    virtual void initialize(Realm&) override;
+    virtual ThrowCompletionOr<void> initialize(Realm&) override;
     virtual ~PluralRulesPrototype() override = default;
 
 private:

Userland/Libraries/LibJS/Runtime/Intl/RelativeTimeFormatConstructor.cpp

@@ -24,9 +24,9 @@ RelativeTimeFormatConstructor::RelativeTimeFormatConstructor(Realm& realm)
 {
 }
 
-void RelativeTimeFormatConstructor::initialize(Realm& realm)
+ThrowCompletionOr<void> RelativeTimeFormatConstructor::initialize(Realm& realm)
 {
-    NativeFunction::initialize(realm);
+    MUST_OR_THROW_OOM(NativeFunction::initialize(realm));
 
     auto& vm = this->vm();
 
@@ -36,6 +36,8 @@ void RelativeTimeFormatConstructor::initialize(Realm& realm)
 
     u8 attr = Attribute::Writable | Attribute::Configurable;
     define_native_function(realm, vm.names.supportedLocalesOf, supported_locales_of, 1, attr);
+
+    return {};
 }
 
 // 17.1.1 Intl.RelativeTimeFormat ( [ locales [ , options ] ] ), https://tc39.es/ecma402/#sec-Intl.RelativeTimeFormat

Userland/Libraries/LibJS/Runtime/Intl/RelativeTimeFormatConstructor.h

@@ -14,7 +14,7 @@ class RelativeTimeFormatConstructor final : public NativeFunction {
     JS_OBJECT(RelativeTimeFormatConstructor, NativeFunction);
 
 public:
-    virtual void initialize(Realm&) override;
+    virtual ThrowCompletionOr<void> initialize(Realm&) override;
     virtual ~RelativeTimeFormatConstructor() override = default;
 
     virtual ThrowCompletionOr<Value> call() override;

Userland/Libraries/LibJS/Runtime/Intl/RelativeTimeFormatPrototype.cpp

@@ -16,9 +16,9 @@ RelativeTimeFormatPrototype::RelativeTimeFormatPrototype(Realm& realm)
 {
 }
 
-void RelativeTimeFormatPrototype::initialize(Realm& realm)
+ThrowCompletionOr<void> RelativeTimeFormatPrototype::initialize(Realm& realm)
 {
-    Object::initialize(realm);
+    MUST_OR_THROW_OOM(Object::initialize(realm));
 
     auto& vm = this->vm();
 
@@ -29,6 +29,8 @@ void RelativeTimeFormatPrototype::initialize(Realm& realm)
     define_native_function(realm, vm.names.format, format, 2, attr);
     define_native_function(realm, vm.names.formatToParts, format_to_parts, 2, attr);
     define_native_function(realm, vm.names.resolvedOptions, resolved_options, 0, attr);
+
+    return {};
 }
 
 // 17.3.3 Intl.RelativeTimeFormat.prototype.format ( value, unit ), https://tc39.es/ecma402/#sec-Intl.RelativeTimeFormat.prototype.format

Userland/Libraries/LibJS/Runtime/Intl/RelativeTimeFormatPrototype.h

@@ -15,7 +15,7 @@ class RelativeTimeFormatPrototype final : public PrototypeObject<RelativeTimeFor
     JS_PROTOTYPE_OBJECT(RelativeTimeFormatPrototype, RelativeTimeFormat, Intl.RelativeTimeFormat);
 
 public:
-    virtual void initialize(Realm&) override;
+    virtual ThrowCompletionOr<void> initialize(Realm&) override;
     virtual ~RelativeTimeFormatPrototype() override = default;
 
 private:

Userland/Libraries/LibJS/Runtime/Intl/SegmentIteratorPrototype.cpp

@@ -18,9 +18,9 @@ SegmentIteratorPrototype::SegmentIteratorPrototype(Realm& realm)
 {
 }
 
-void SegmentIteratorPrototype::initialize(Realm& realm)
+ThrowCompletionOr<void> SegmentIteratorPrototype::initialize(Realm& realm)
 {
-    Object::initialize(realm);
+    MUST_OR_THROW_OOM(Object::initialize(realm));
 
     auto& vm = this->vm();
 
@@ -29,6 +29,8 @@ void SegmentIteratorPrototype::initialize(Realm& realm)
 
     u8 attr = Attribute::Writable | Attribute::Configurable;
     define_native_function(realm, vm.names.next, next, 0, attr);
+
+    return {};
 }
 
 // 18.6.2.1 %SegmentIteratorPrototype%.next ( ), https://tc39.es/ecma402/#sec-%segmentiteratorprototype%.next

Userland/Libraries/LibJS/Runtime/Intl/SegmentIteratorPrototype.h

@@ -15,7 +15,7 @@ class SegmentIteratorPrototype final : public PrototypeObject<SegmentIteratorPro
     JS_PROTOTYPE_OBJECT(SegmentIteratorPrototype, SegmentIterator, SegmentIterator);
 
 public:
-    virtual void initialize(Realm&) override;
+    virtual ThrowCompletionOr<void> initialize(Realm&) override;
     virtual ~SegmentIteratorPrototype() override = default;
 
 private:

Userland/Libraries/LibJS/Runtime/Intl/SegmenterConstructor.cpp

@@ -21,9 +21,9 @@ SegmenterConstructor::SegmenterConstructor(Realm& realm)
 {
 }
 
-void SegmenterConstructor::initialize(Realm& realm)
+ThrowCompletionOr<void> SegmenterConstructor::initialize(Realm& realm)
 {
-    NativeFunction::initialize(realm);
+    MUST_OR_THROW_OOM(NativeFunction::initialize(realm));
 
     auto& vm = this->vm();
 
@@ -33,6 +33,8 @@ void SegmenterConstructor::initialize(Realm& realm)
 
     u8 attr = Attribute::Writable | Attribute::Configurable;
     define_native_function(realm, vm.names.supportedLocalesOf, supported_locales_of, 1, attr);
+
+    return {};
 }
 
 // 18.1.1 Intl.Segmenter ( [ locales [ , options ] ] ), https://tc39.es/ecma402/#sec-intl.segmenter

Userland/Libraries/LibJS/Runtime/Intl/SegmenterConstructor.h

@@ -14,7 +14,7 @@ class SegmenterConstructor final : public NativeFunction {
     JS_OBJECT(SegmenterConstructor, NativeFunction);
 
 public:
-    virtual void initialize(Realm&) override;
+    virtual ThrowCompletionOr<void> initialize(Realm&) override;
     virtual ~SegmenterConstructor() override = default;
 
     virtual ThrowCompletionOr<Value> call() override;

Userland/Libraries/LibJS/Runtime/Intl/SegmenterPrototype.cpp

@@ -17,9 +17,9 @@ SegmenterPrototype::SegmenterPrototype(Realm& realm)
 {
 }
 
-void SegmenterPrototype::initialize(Realm& realm)
+ThrowCompletionOr<void> SegmenterPrototype::initialize(Realm& realm)
 {
-    Object::initialize(realm);
+    MUST_OR_THROW_OOM(Base::initialize(realm));
 
     auto& vm = this->vm();
 
@@ -29,6 +29,8 @@ void SegmenterPrototype::initialize(Realm& realm)
     u8 attr = Attribute::Writable | Attribute::Configurable;
     define_native_function(realm, vm.names.resolvedOptions, resolved_options, 0, attr);
     define_native_function(realm, vm.names.segment, segment, 1, attr);
+
+    return {};
 }
 
 // 18.3.4 Intl.Segmenter.prototype.resolvedOptions ( ), https://tc39.es/ecma402/#sec-intl.segmenter.prototype.resolvedoptions

Userland/Libraries/LibJS/Runtime/Intl/SegmenterPrototype.h

@@ -15,7 +15,7 @@ class SegmenterPrototype final : public PrototypeObject<SegmenterPrototype, Segm
     JS_PROTOTYPE_OBJECT(SegmenterPrototype, Segmenter, Segmenter);
 
 public:
-    virtual void initialize(Realm&) override;
+    virtual ThrowCompletionOr<void> initialize(Realm&) override;
     virtual ~SegmenterPrototype() override = default;
 
 private:

Userland/Libraries/LibJS/Runtime/Intl/SegmentsPrototype.cpp

@@ -17,15 +17,17 @@ SegmentsPrototype::SegmentsPrototype(Realm& realm)
 {
 }
 
-void SegmentsPrototype::initialize(Realm& realm)
+ThrowCompletionOr<void> SegmentsPrototype::initialize(Realm& realm)
 {
-    Object::initialize(realm);
+    MUST_OR_THROW_OOM(Base::initialize(realm));
 
     auto& vm = this->vm();
 
     u8 attr = Attribute::Writable | Attribute::Configurable;
     define_native_function(realm, *vm.well_known_symbol_iterator(), symbol_iterator, 0, attr);
     define_native_function(realm, vm.names.containing, containing, 1, attr);
+
+    return {};
 }
 
 // 18.5.2.1 %SegmentsPrototype%.containing ( index ), https://tc39.es/ecma402/#sec-%segmentsprototype%.containing

Userland/Libraries/LibJS/Runtime/Intl/SegmentsPrototype.h

@@ -15,7 +15,7 @@ class SegmentsPrototype final : public PrototypeObject<SegmentsPrototype, Segmen
     JS_PROTOTYPE_OBJECT(SegmentsPrototype, Segments, Segments);
 
 public:
-    virtual void initialize(Realm&) override;
+    virtual ThrowCompletionOr<void> initialize(Realm&) override;
     virtual ~SegmentsPrototype() override = default;
 
 private: