revert e1ffbae because of #368

Author: zloirock

modules/_iter-define.js

@@ -30,7 +30,7 @@ module.exports = function (Base, NAME, Constructor, next, DEFAULT, IS_SET, FORCE
   var VALUES_BUG = false;
   var proto = Base.prototype;
   var $native = proto[ITERATOR] || proto[FF_ITERATOR] || DEFAULT && proto[DEFAULT];
-  var $default = (!BUGGY && $native) || getMethod(DEFAULT);
+  var $default = $native || getMethod(DEFAULT);
   var $entries = DEFAULT ? !DEF_VALUES ? $default : getMethod('entries') : undefined;
   var $anyNative = NAME == 'Array' ? proto.entries || $native : $native;
   var methods, key, IteratorPrototype;