[DDP] Log when errors happen (#59281)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/59281
Adds ability to log when reducer/ddp encounters an error. We add fields "has_error" and "error" to indicate that an error has
occured in this iteration, and the other fields (performance stats) are not
guaranteed to be updated.
Errors encountered in python-side DDP will be added in the next diff.
ghstack-source-id: 130412974
Test Plan: CI
Reviewed By: mrshenli
Differential Revision: D28652717
fbshipit-source-id: 9772abc2647a92dac6a325da6976ef5eb877c589
