LibJS+LibWeb: Let Realm store a plain Object for [[GlobalObject]]

This removes the requirement of having a global object that actually
inherits from JS::GlobalObject, which is now a perfectly valid scenario.

With the upcoming removal of wrapper objects in LibWeb, the HTML::Window
object will inherit from DOM::EventTarget, which means it cannot also
inherit from JS::GlobalObject.

Userland/Libraries/LibJS/Runtime/Realm.cpp

@@ -32,7 +32,7 @@ Realm* Realm::create(VM& vm)
 }
 
 // 9.6 InitializeHostDefinedRealm ( ), https://tc39.es/ecma262/#sec-initializehostdefinedrealm
-ThrowCompletionOr<NonnullOwnPtr<ExecutionContext>> Realm::initialize_host_defined_realm(VM& vm, Function<GlobalObject*(Realm&)> create_global_object, Function<GlobalObject*(Realm&)> create_global_this_value)
+ThrowCompletionOr<NonnullOwnPtr<ExecutionContext>> Realm::initialize_host_defined_realm(VM& vm, Function<Object*(Realm&)> create_global_object, Function<Object*(Realm&)> create_global_this_value)
 {
     DeferGC defer_gc(vm.heap());
 
@@ -57,14 +57,14 @@ ThrowCompletionOr<NonnullOwnPtr<ExecutionContext>> Realm::initialize_host_define
     // 7. If the host requires use of an exotic object to serve as realm's global object,
     //    let global be such an object created in a host-defined manner.
     //    Otherwise, let global be undefined, indicating that an ordinary object should be created as the global object.
-    GlobalObject* global = nullptr;
+    Object* global = nullptr;
     if (create_global_object)
         global = create_global_object(*realm);
 
     // 8. If the host requires that the this binding in realm's global scope return an object other than the global object,
     //    let thisValue be such an object created in a host-defined manner.
     //    Otherwise, let thisValue be undefined, indicating that realm's global this binding should be the global object.
-    GlobalObject* this_value = nullptr;
+    Object* this_value = nullptr;
     if (create_global_this_value)
         this_value = create_global_this_value(*realm);
 
@@ -82,7 +82,7 @@ ThrowCompletionOr<NonnullOwnPtr<ExecutionContext>> Realm::initialize_host_define
 }
 
 // 9.3.3 SetRealmGlobalObject ( realmRec, globalObj, thisValue ), https://tc39.es/ecma262/#sec-setrealmglobalobject
-void Realm::set_global_object(GlobalObject* global_object, GlobalObject* this_value)
+void Realm::set_global_object(Object* global_object, Object* this_value)
 {
     // 1. If globalObj is undefined, then
     if (global_object == nullptr) {

Userland/Libraries/LibJS/Runtime/Realm.h

@@ -28,11 +28,11 @@ public:
     Realm() = default;
 
     static Realm* create(VM&);
-    static ThrowCompletionOr<NonnullOwnPtr<ExecutionContext>> initialize_host_defined_realm(VM&, Function<GlobalObject*(Realm&)> create_global_object, Function<GlobalObject*(Realm&)> create_global_this_value);
+    static ThrowCompletionOr<NonnullOwnPtr<ExecutionContext>> initialize_host_defined_realm(VM&, Function<Object*(Realm&)> create_global_object, Function<Object*(Realm&)> create_global_this_value);
 
-    void set_global_object(GlobalObject* global_object, GlobalObject* this_value);
+    void set_global_object(Object* global_object, Object* this_value);
 
-    [[nodiscard]] GlobalObject& global_object() const { return *m_global_object; }
+    [[nodiscard]] Object& global_object() const { return *m_global_object; }
     [[nodiscard]] GlobalEnvironment& global_environment() const { return *m_global_environment; }
 
     [[nodiscard]] Intrinsics const& intrinsics() const { return *m_intrinsics; }
@@ -51,7 +51,7 @@ private:
     virtual void visit_edges(Visitor&) override;
 
     Intrinsics* m_intrinsics { nullptr };                // [[Intrinsics]]
-    GlobalObject* m_global_object { nullptr };           // [[GlobalObject]]
+    Object* m_global_object { nullptr };                 // [[GlobalObject]]
     GlobalEnvironment* m_global_environment { nullptr }; // [[GlobalEnv]]
     OwnPtr<HostDefined> m_host_defined;                  // [[HostDefined]]
 };

Userland/Libraries/LibJS/Runtime/VM.cpp

@@ -644,7 +644,7 @@ Value VM::get_new_target()
 }
 
 // 9.4.5 GetGlobalObject ( ), https://tc39.es/ecma262/#sec-getglobalobject
-GlobalObject& VM::get_global_object()
+Object& VM::get_global_object()
 {
     // 1. Let currentRealm be the current Realm Record.
     auto& current_realm = *this->current_realm();

Userland/Libraries/LibJS/Runtime/VM.h

@@ -186,7 +186,7 @@ public:
 
     Value get_new_target();
 
-    GlobalObject& get_global_object();
+    Object& get_global_object();
 
     CommonPropertyNames names;