gh-123958: apply docstring removal optimization in ast_opt instead of codegen

[iritkatriel]

• Issue: codegen should ideally not need to know the optimization level #123958

[JelleZijlstra]

Do we have a test case like this?

def f():
    "docstring"
    "some random string"

I haven't checked but your code looks like it may end up putting some random string in __doc__.

[iritkatriel]

Do we have a test case like this?

def f():
    "docstring"
    "some random string"

I haven't checked but your code looks like it may end up putting some random string in __doc__.

It would turn some random string into an f-string to prevent that. I agree we should have this test.