Handling of failing and terminal async cpu ops (#29052)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/29052
Make sure we handle the case of multiple, async, terminal (no children)
and failing cpu ops.
Test Plan: AsyncIf tests
Reviewed By: yyetim
Differential Revision: D18276401
Pulled By: ilia-cher
fbshipit-source-id: 35b175dd025bc7e392056ac1331b159376a29e60
