Pickle will prefer the __reduce_ex__() method over the __reduce__() method. If base class defined the __reduce_ex__() method, Enum.__reduce__() will be ignored.

> I left the test for test_subclasses_without_getnewargs alone as the point of that test is to make sure that _make_class_unpicklable is working properly, not to see if we can somehow get any of it to pickle.

Without these changes pickling failed, but not because _make_class_unpicklable.

I added other comments on Rietveld.