reland [es7] refactor and fix Object.values() / Object.entries()

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 9cd251b2858032c58a163ba774eb63d096d678f9..f77c7e060f755c83a3e85db568c05911d85f456a 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -1960,6 +1960,12 @@ class JSReceiver: public HeapObject {
       Handle<JSReceiver> object, KeyCollectionType type, PropertyFilter filter,
       GetKeysConversion keys_conversion = KEEP_NUMBERS);
 
+  MUST_USE_RESULT static MaybeHandle<FixedArray> GetOwnValues(
+      Handle<JSReceiver> object, PropertyFilter filter);
+
+  MUST_USE_RESULT static MaybeHandle<FixedArray> GetOwnEntries(
+      Handle<JSReceiver> object, PropertyFilter filter);
+
   // Layout description.
   static const int kPropertiesOffset = HeapObject::kHeaderSize;
   static const int kHeaderSize = HeapObject::kHeaderSize + kPointerSize;