Move SetObjectPrototype to JSObject

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index d79f4eaf9776de65242fd6a71c9048262db222d0..5b479a36ebfa3b7f3f5b4d89477ce72fa514082d 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -2308,6 +2308,9 @@ class JSObject: public JSReceiver {
   static void MigrateToMap(Handle<JSObject> object, Handle<Map> new_map,
                            int expected_additional_properties = 0);
 
+  // object.__proto__ = proto;
+  static void SetObjectPrototype(Handle<JSObject> object, Handle<Object> proto);
+
   // Convert the object to use the canonical dictionary
   // representation. If the object is expected to have additional properties
   // added this number can be indicated to have the backing store allocated to