Add autograd tests for addmm, addmv, mm, mv and CSR matrix input (#71949)
Summary:
This PR adds autograd tests for `addmm, addmv, mm, mv` functions that check computing derivatives wrt dense inputs.
Currently, neither autograd engine, nor gradcheck can work with CSR inputs<->CSR outputs. I added xfailing tests for that.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/71949
Reviewed By: george-qi
Differential Revision: D33834653
Pulled By: cpuhrsch
fbshipit-source-id: 4144c1547427d4cd6b01495cf45242bb4e914e86
(cherry picked from commit 2cb362283d247c0628a242ab65335d927b7fdec7)
