Add NCCL Alltoall to PT NCCL process group (#42514)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/42514
Add Alltoall and Alltoallv to PT NCCL process group using NCCL Send/Recv.
Reviewed By: mrshenli
Differential Revision: D22917967
fbshipit-source-id: 402f2870915bc237845864a4a27c97df4351d975
Author
Srinivas Sridharan
