Add NCCL Alltoall to PT NCCL process group (#39984)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/39984
Add Alltoall and Alltoallv to PT NCCL process group using NCCL Send/Recv.
Reviewed By: jiayisuse
Differential Revision: D20781624
fbshipit-source-id: 109436583ff69a3fea089703d32cfc5a75f973e0
Author
Srinivas Sridharan
