gh-91621: Fix typing.get_type_hints for collections.abc.Callable (#91656)

This mirrors logic in typing.get_args. The trickiness comes from how we
flatten args in collections.abc.Callable, see
https://bugs.python.org/issue42195

Shantanu committed 4y ago

ebb8b512e959ca1a0a506ac0f0faf461b1b2ff85

Parent: aff8c4f

Committed by GitHub <noreply@github.com> on 5/2/2022, 11:08:28 PM