Add some reduction forward AD formulas (#69661)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/69661
Test Plan: Imported from OSS
Reviewed By: albanD
Differential Revision: D33020601
Pulled By: soulitzer
fbshipit-source-id: 110da6dcd490e5c3849cace62a777aa1a2b6982e
