[3.9] bpo-42057: Fix peephole optimizer

[methane]

https://bugs.python.org/issue42057

[markshannon]

Looks good.
Could you add the following test to test_peepholer.py

def test_42057():
    for i in range(10):
         try:
             raise Exception
         except Exception or Exception:
             pass

Putting the try-except in a loop causes a consistent crash due to stack underflow.

[methane]

Oh, I'm sorrry. I forget to push the requested test case.

[methane]

Ah! I had pushed it to python/cpython repository instead of my fork.

[methane]

#22878