[proxies] use [[GetPrototypeOf]] trap in for-in

src/objects-inl.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // Review notes:
 //
 // - The use of macros in these inline functions may seem superfluous
 // but it is absolutely needed to make sure gcc generates optimal
 // code. gcc is not happy when attempting to inline too deep.
 //
@@ skipping 7053 matching lines @@
   return !properties()->IsDictionary();
 }
 
 
 NameDictionary* JSReceiver::property_dictionary() {
   DCHECK(!HasFastProperties());
   DCHECK(!IsJSGlobalObject());
   return NameDictionary::cast(properties());
 }
 
-
 Maybe<bool> JSReceiver::HasProperty(Handle<JSReceiver> object,
                                     Handle<Name> name) {
   LookupIterator it = LookupIterator::PropertyOrElement(object->GetIsolate(),
                                                         object, name, object);
   return HasProperty(&it);
 }
 
 
 Maybe<bool> JSReceiver::HasOwnProperty(Handle<JSReceiver> object,
                                        Handle<Name> name) {
@@ skipping 704 matching lines @@
 #undef WRITE_INT64_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 #undef NOBARRIER_READ_BYTE_FIELD
 #undef NOBARRIER_WRITE_BYTE_FIELD
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_OBJECTS_INL_H_