LibJS: Add preparation for Temporal constructors and prototypes

Add a JS_ENUMERATE_TEMPORAL_OBJECTS macro and use it to generate:

- Forward declarations
- CommonPropertyNames class name members
- Constructor and prototype GlobalObject members, getters, visitors,
  and initialize_constructor() calls

Userland/Libraries/LibJS/Forward.h

@@ -76,6 +76,8 @@
     __JS_ENUMERATE(Float32Array, float32_array, Float32ArrayPrototype, Float32ArrayConstructor, float)                          \
     __JS_ENUMERATE(Float64Array, float64_array, Float64ArrayPrototype, Float64ArrayConstructor, double)
 
+#define JS_ENUMERATE_TEMPORAL_OBJECTS
+
 #define JS_ENUMERATE_ITERATOR_PROTOTYPES          \
     __JS_ENUMERATE(Iterator, iterator)            \
     __JS_ENUMERATE(ArrayIterator, array_iterator) \
@@ -185,6 +187,15 @@ JS_ENUMERATE_NATIVE_ERRORS
 JS_ENUMERATE_TYPED_ARRAYS
 #undef __JS_ENUMERATE
 
+namespace Temporal {
+#define __JS_ENUMERATE(ClassName, snake_name, ConstructorName, PrototypeName) \
+    class ClassName;                                                          \
+    class ConstructorName;                                                    \
+    class PrototypeName;
+JS_ENUMERATE_TEMPORAL_OBJECTS
+#undef __JS_ENUMERATE
+};
+
 template<class T>
 class Handle;
 

Userland/Libraries/LibJS/Runtime/CommonPropertyNames.h

@@ -344,6 +344,9 @@ struct CommonPropertyNames {
 #define __JS_ENUMERATE(x, a, b, c, t) PropertyName x { #x, PropertyName::StringMayBeNumber::No };
     JS_ENUMERATE_BUILTIN_TYPES
 #undef __JS_ENUMERATE
+#define __JS_ENUMERATE(x, a, b, c) PropertyName x { #x, PropertyName::StringMayBeNumber::No };
+    JS_ENUMERATE_TEMPORAL_OBJECTS
+#undef __JS_ENUMERATE
 #define __JS_ENUMERATE(x, a) PropertyName x { #x, PropertyName::StringMayBeNumber::No };
     JS_ENUMERATE_WELL_KNOWN_SYMBOLS
 #undef __JS_ENUMERATE

Userland/Libraries/LibJS/Runtime/GlobalObject.cpp

@@ -133,6 +133,18 @@ void GlobalObject::initialize_global_object()
     JS_ENUMERATE_BUILTIN_TYPES
 #undef __JS_ENUMERATE
 
+#define __JS_ENUMERATE(ClassName, snake_name, PrototypeName, ConstructorName) \
+    if (!m_temporal_##snake_name##_prototype)                                 \
+        m_temporal_##snake_name##_prototype = heap().allocate<Temporal::PrototypeName>(*this, *this);
+    JS_ENUMERATE_TEMPORAL_OBJECTS
+#undef __JS_ENUMERATE
+
+    // Must be allocated before `Temporal::Temporal` below.
+#define __JS_ENUMERATE(ClassName, snake_name, PrototypeName, ConstructorName) \
+    initialize_constructor(vm.names.ClassName, m_temporal_##snake_name##_constructor, m_temporal_##snake_name##_prototype);
+    JS_ENUMERATE_TEMPORAL_OBJECTS
+#undef __JS_ENUMERATE
+
     u8 attr = Attribute::Writable | Attribute::Configurable;
     define_native_function(vm.names.gc, gc, 0, attr);
     define_native_function(vm.names.isNaN, is_nan, 1, attr);
@@ -235,6 +247,12 @@ void GlobalObject::visit_edges(Visitor& visitor)
     JS_ENUMERATE_BUILTIN_TYPES
 #undef __JS_ENUMERATE
 
+#define __JS_ENUMERATE(ClassName, snake_name, PrototypeName, ConstructorName) \
+    visitor.visit(m_temporal_##snake_name##_constructor);                     \
+    visitor.visit(m_temporal_##snake_name##_prototype);
+    JS_ENUMERATE_TEMPORAL_OBJECTS
+#undef __JS_ENUMERATE
+
 #define __JS_ENUMERATE(ClassName, snake_name) \
     visitor.visit(m_##snake_name##_prototype);
     JS_ENUMERATE_ITERATOR_PROTOTYPES

Userland/Libraries/LibJS/Runtime/GlobalObject.h

@@ -46,6 +46,12 @@ public:
     JS_ENUMERATE_BUILTIN_TYPES
 #undef __JS_ENUMERATE
 
+#define __JS_ENUMERATE(ClassName, snake_name, PrototypeName, ConstructorName)                                          \
+    Temporal::ConstructorName* temporal_##snake_name##_constructor() { return m_temporal_##snake_name##_constructor; } \
+    Object* temporal_##snake_name##_prototype() { return m_temporal_##snake_name##_prototype; }
+    JS_ENUMERATE_TEMPORAL_OBJECTS
+#undef __JS_ENUMERATE
+
 #define __JS_ENUMERATE(ClassName, snake_name) \
     Object* snake_name##_prototype() { return m_##snake_name##_prototype; }
     JS_ENUMERATE_ITERATOR_PROTOTYPES
@@ -95,6 +101,12 @@ private:
     JS_ENUMERATE_BUILTIN_TYPES
 #undef __JS_ENUMERATE
 
+#define __JS_ENUMERATE(ClassName, snake_name, PrototypeName, ConstructorName)     \
+    Temporal::ConstructorName* m_temporal_##snake_name##_constructor { nullptr }; \
+    Object* m_temporal_##snake_name##_prototype { nullptr };
+    JS_ENUMERATE_TEMPORAL_OBJECTS
+#undef __JS_ENUMERATE
+
 #define __JS_ENUMERATE(ClassName, snake_name) \
     Object* m_##snake_name##_prototype { nullptr };
     JS_ENUMERATE_ITERATOR_PROTOTYPES