PEP 709 behavior change around mangling #104604

>>> class __a:
...     __a = (1)[[__a for __b in [1]]] = 1
... 
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 2, in __a
TypeError: 'int' object does not support item assignment

>>> class __a:
...     __a = (1)[[__a for __b in [1]]] = 1
... 
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 2, in __a
  File "<stdin>", line 2, in <listcomp>
NameError: name '_a__a' is not defined. Did you mean: '_a__b'?