Support torch.distributed.irecv(src=None, ...) (#47137)
Summary:
Calling torch.distributed.irecv(src=None) fails with "The global rank None is not part of the group". This change calls recv_anysource if src is None. Tested locally with MPI backend.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/47137
Reviewed By: heitorschueroff
Differential Revision: D25292656
fbshipit-source-id: beb018ba0b676924aeaabeb4a4d6acf96e4a1926
