Scope pybind11 functions to torch.distributed.{autograd,rpc}
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/27529
Test Plan: Imported from OSS
Differential Revision: D17808209
Pulled By: pietern
fbshipit-source-id: 1e3e086085167320c3fc369467f5d75ce39fa4ea
