[api] Make ObjectTemplate::SetNativeDataProperty() work even if the ObjectTemplate does not have a …

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index ab6fa54859416d80a4601f1d25358bfe2cbd5221..b2609ba8304b50d57226f7ed5790fae5e5c2bf9d 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -8236,6 +8236,25 @@ MaybeHandle<JSObject> JSObject::DeepCopy(
   return copy;
 }
 
+class DummyContextObject : public AllocationSiteContext {
+ public:
+  explicit DummyContextObject(Isolate* isolate)
+      : AllocationSiteContext(isolate) {}
+
+  bool ShouldCreateMemento(Handle<JSObject> object) { return false; }
+  Handle<AllocationSite> EnterNewScope() { return Handle<AllocationSite>(); }
+  void ExitScope(Handle<AllocationSite> site, Handle<JSObject> object) {}
+};
+
+MaybeHandle<JSObject> JSObject::DeepCopy(Handle<JSObject> object,
+                                         DeepCopyHints hints) {
+  DummyContextObject dummy_context_object(object->GetIsolate());
+  JSObjectWalkVisitor<DummyContextObject> v(&dummy_context_object, true, hints);
+  MaybeHandle<JSObject> copy = v.StructureWalk(object);
+  Handle<JSObject> for_assert;
+  DCHECK(!copy.ToHandle(&for_assert) || !for_assert.is_identical_to(object));
+  return copy;
+}
 
 // static
 MaybeHandle<Object> JSReceiver::ToPrimitive(Handle<JSReceiver> receiver,