Class B_with_slots_dict_weakref

Lib/test/test_descr.py:4270–4271

        self.assertEqual(repr(b), '<A>')

        class B_with_slots_dict_weakref:
            __slots__ = ('x', '__dict__', '__weakref__')
        b = B_with_slots_dict_weakref()
        with self.assertRaisesRegex(TypeError, 'layout differs'):
            B_with_slots_dict_weakref.__bases__ = (A_with_slots_dict,)