[es6] Partially implement Reflect.getOwnPropertyDescriptor.

src/objects.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.
 
 #ifndef V8_OBJECTS_H_
 #define V8_OBJECTS_H_
 
 #include <iosfwd>
 
 #include "src/allocation.h"
@@ skipping 1875 matching lines @@
   static bool OrdinaryDefineOwnProperty(Isolate* isolate,
                                         Handle<JSObject> object,
                                         Handle<Object> key,
                                         PropertyDescriptor* desc,
                                         ShouldThrow should_throw);
   static bool OrdinaryDefineOwnProperty(LookupIterator* it,
                                         PropertyDescriptor* desc,
                                         ShouldThrow should_throw);
 
   static bool GetOwnPropertyDescriptor(Isolate* isolate,
-                                       Handle<JSObject> object,
+                                       Handle<JSReceiver> object,
                                        Handle<Object> key,
                                        PropertyDescriptor* desc);
   static bool GetOwnPropertyDescriptor(LookupIterator* it,
                                        PropertyDescriptor* desc);
 
   // Disallow further properties to be added to the object.  This is
   // ES6's [[PreventExtensions]] when passed DONT_THROW.
   MUST_USE_RESULT static Maybe<bool> PreventExtensions(
       Handle<JSReceiver> object, ShouldThrow should_throw);
 
@@ skipping 8929 matching lines @@
   // (elements + properties) in the current level.
   int levelLength_;
 
   DISALLOW_COPY_AND_ASSIGN(KeyAccumulator);
 };
 
 }  // NOLINT, false-positive due to second-order macros.
 }  // NOLINT, false-positive due to second-order macros.
 
 #endif  // V8_OBJECTS_H_