Add GetPropertyAttribute method for Object in the API

src/handles.cc

Index: src/handles.cc
diff --git a/src/handles.cc b/src/handles.cc
index d73aaf0fca671fed228d4996c5e70872713eee8e..c22ad4cde66b08c57f87c304dc382600dc4f896b 100644
--- a/src/handles.cc
+++ b/src/handles.cc
@@ -390,6 +390,13 @@ Handle<Object> GetElement(Handle<Object> obj,
 }
 
 
+PropertyAttributes GetPropertyAttribute(Handle<JSObject> obj,
+                                        Handle<Object> key,
+                                        bool* has_pending_exception) {
+  return obj->TryGetPropertyAttribute(key, has_pending_exception);
+}
+
+
 Handle<Object> GetPropertyWithInterceptor(Handle<JSObject> receiver,
                                           Handle<JSObject> holder,
                                           Handle<String> name,