[Pytorch Edge] Refactor Compatibility Stuff into own directory (#71432)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/71432
Organizing jit/mobile a little more
ghstack-source-id: 147184536
Test Plan: ci.
Reviewed By: iseeyuan
Differential Revision: D33640527
fbshipit-source-id: f3a7884fe0d06d80bb8d9cf141ecaee34b6f88ff
(cherry picked from commit 4c3d1e5435db04a4ca2898ddf0811490f5959555)
