Use LookupIterator to transition to accessors

src/runtime.cc

Index: src/runtime.cc
diff --git a/src/runtime.cc b/src/runtime.cc
index 87d8ce4a517c96ccfd35a6fe8c737389f146238f..4aeef9d4558b7a59c3dcb06aa3d2d8052d022b92 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -4948,7 +4948,7 @@ static bool IsValidAccessor(Handle<Object> obj) {
 // Transform getter or setter into something DefineAccessor can handle.
 static Handle<Object> InstantiateAccessorComponent(Isolate* isolate,
                                                    Handle<Object> component) {
-  if (component->IsUndefined()) return isolate->factory()->null_value();
+  if (component->IsUndefined()) return isolate->factory()->undefined_value();
   Handle<FunctionTemplateInfo> info =
       Handle<FunctionTemplateInfo>::cast(component);
   return Utils::OpenHandle(*Utils::ToLocal(info)->GetFunction());