change nccl version reporting (#62916)
Summary:
https://github.com/pytorch/pytorch/issues/62295
Previously the packing and unpacking of the NCCL version "integer" was done to have parity with the upstream NCCL version encoding. However, there doesn't seem to be any place where this integer is directly compared with a version integer sourced from upstream NCCL, and syncing the encoding seems to be error-prone (e.g., a recent change where a special case was added for minor versions >= 10 https://github.com/NVIDIA/nccl/blob/7e515921295adaab72adf56ea71a0fafb0ecb5f3/src/nccl.h.in#L22).
This patch changes the reporting to return a tuple of version numbers instead (to preserve ease-of-use for comparisons) and tweaks the passing between C/Python to avoid the digit overflow problem.
CC ngimel mcarilli
Pull Request resolved: https://github.com/pytorch/pytorch/pull/62916
Reviewed By: anjali411
Differential Revision: D30201069
Pulled By: mrshenli
fbshipit-source-id: 2e4e7c69f001c3f22bd04aa6df6a992e538bea45
