`*_solve` methods: implements forward AD (#65546)
Summary:
This PR adds forward AD for `*_solve` methods.
Additionally, `cholesky_solve` gets OpInfo + a bug fix when wrong leading dimensions could be passed to LAPACK,
and `lu_solve` gets forward AD with 2x`lu_solve` instead of 1x`lu_solve` + 2x`triangular_solve`.
cc ezyang albanD zou3519 gqchen pearu nikitaved soulitzer Lezcano Varal7 jianyuh mruberry walterddr IvanYashchuk xwang233
Pull Request resolved: https://github.com/pytorch/pytorch/pull/65546
Reviewed By: dagitses
Differential Revision: D31431847
Pulled By: albanD
fbshipit-source-id: 0e343e0d9da3c3d2051fca215fad289d77275251
