LibJS: Implement a nearly empty Intl.NumberFormat object

This adds plumbing for the Intl.NumberFormat object, constructor, and
prototype.

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

@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2021, Tim Flynn <trflynn89@pm.me>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibJS/Runtime/AbstractOperations.h>
+#include <LibJS/Runtime/GlobalObject.h>
+#include <LibJS/Runtime/Intl/NumberFormat.h>
+#include <LibJS/Runtime/Intl/NumberFormatConstructor.h>
+
+namespace JS::Intl {
+
+// 15.2 The Intl.NumberFormat Constructor, https://tc39.es/ecma402/#sec-intl-numberformat-constructor
+NumberFormatConstructor::NumberFormatConstructor(GlobalObject& global_object)
+    : NativeFunction(vm().names.NumberFormat.as_string(), *global_object.function_prototype())
+{
+}
+
+void NumberFormatConstructor::initialize(GlobalObject& global_object)
+{
+    NativeFunction::initialize(global_object);
+
+    auto& vm = this->vm();
+
+    // 15.3.1 Intl.NumberFormat.prototype, https://tc39.es/ecma402/#sec-intl.numberformat.prototype
+    define_direct_property(vm.names.prototype, global_object.intl_number_format_prototype(), 0);
+    define_direct_property(vm.names.length, Value(0), Attribute::Configurable);
+}
+
+// 15.2.1 Intl.NumberFormat ( [ locales [ , options ] ] ), https://tc39.es/ecma402/#sec-intl.numberformat
+Value NumberFormatConstructor::call()
+{
+    // 1. If NewTarget is undefined, let newTarget be the active function object, else let newTarget be NewTarget.
+    return construct(*this);
+}
+
+// 15.2.1 Intl.NumberFormat ( [ locales [ , options ] ] ), https://tc39.es/ecma402/#sec-intl.numberformat
+Value NumberFormatConstructor::construct(FunctionObject& new_target)
+{
+    auto& vm = this->vm();
+    auto& global_object = this->global_object();
+
+    // 2. Let numberFormat be ? OrdinaryCreateFromConstructor(newTarget, "%NumberFormat.prototype%", « [[InitializedNumberFormat]], [[Locale]], [[DataLocale]], [[NumberingSystem]], [[Style]], [[Unit]], [[UnitDisplay]], [[Currency]], [[CurrencyDisplay]], [[CurrencySign]], [[MinimumIntegerDigits]], [[MinimumFractionDigits]], [[MaximumFractionDigits]], [[MinimumSignificantDigits]], [[MaximumSignificantDigits]], [[RoundingType]], [[Notation]], [[CompactDisplay]], [[UseGrouping]], [[SignDisplay]], [[BoundFormat]] »).
+    auto* number_format = ordinary_create_from_constructor<NumberFormat>(global_object, new_target, &GlobalObject::intl_number_format_prototype);
+    if (vm.exception())
+        return {};
+
+    // 5. Return numberFormat.
+    return number_format;
+}
+
+}