symeig supports complex backward (#55085)
Summary:
Fixes https://github.com/pytorch/pytorch/issues/53651
I did not put much effort in improving the docs, as I will go over all these docs in future PRs
cc anjali411
Pull Request resolved: https://github.com/pytorch/pytorch/pull/55085
Reviewed By: nikithamalgifb
Differential Revision: D27493604
Pulled By: anjali411
fbshipit-source-id: 413363013e188bc869c404b2d54ce1f87eef4425
