Introduce v8::Object::CreateDataProperty

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 4301775086c73827cc58d9dfdb86102de244baa8..2eddaeaeb57a11b9ed5966172f1ece7b4a98d73d 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -5743,6 +5743,17 @@ MaybeHandle<Object> JSObject::PreventExtensions(Handle<JSObject> object) {
 }
 
 
+bool JSObject::IsExtensible() {
+  if (IsJSGlobalProxy()) {
+    PrototypeIterator iter(GetIsolate(), this);
+    if (iter.IsAtEnd()) return false;
+    DCHECK(iter.GetCurrent()->IsJSGlobalObject());
+    return JSObject::cast(iter.GetCurrent())->map()->is_extensible();
+  }
+  return map()->is_extensible();
+}
+
+
 Handle<SeededNumberDictionary> JSObject::GetNormalizedElementDictionary(
     Handle<JSObject> object) {
   DCHECK(!object->elements()->IsDictionary());