LibJS: Move intrinsics to the realm

Intrinsics, i.e. mostly constructor and prototype objects, but also
things like empty and new object shape now live on a new heap-allocated
JS::Intrinsics object, thus completing the long journey of taking all
the magic away from the global object.
This represents the Realm's [[Intrinsics]] slot in the spec and matches
its existing [[GlobalObject]] / [[GlobalEnv]] slots in terms of
architecture.

In the majority of cases it should now be possibly to fully allocate a
regular object without the global object existing, and in fact that's
what we do now - the realm is allocated before the global object, and
the intrinsics between both :^)

Userland/Libraries/LibJS/Runtime/VM.cpp

@@ -336,7 +336,7 @@ ThrowCompletionOr<void> VM::property_binding_initialization(BindingPattern const
                 VERIFY_NOT_REACHED();
             }
 
-            auto* rest_object = Object::create(realm, realm.global_object().object_prototype());
+            auto* rest_object = Object::create(realm, realm.intrinsics().object_prototype());
             VERIFY(rest_object);
 
             TRY(rest_object->copy_data_properties(vm, object, seen_names));