Implement rad2deg, deg2rad (#38852)
Summary:
Resolves https://github.com/pytorch/pytorch/issues/38372.
cc mruberry
Pull Request resolved: https://github.com/pytorch/pytorch/pull/38852
Differential Revision: D21868935
Pulled By: mruberry
fbshipit-source-id: ae6ded11b743c9d1cdc032984b4abe0a115290d6
