Adding in Wrap functions for FSDP from Fairscale (#67292)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/67292
as title
Test Plan: buck test mode/dev-nosan //caffe2/test/distributed/fsdp:wrap --keep-going
Reviewed By: rohan-varma
Differential Revision: D31936404
fbshipit-source-id: b7ebead9a649766aec83e5630c2ce1386ad33e11
