Revert "Revert D30558877: Ported std/var to ReductionOpInfo (#65262)
Summary:
Reland of https://github.com/pytorch/pytorch/issues/63978
Pull Request resolved: https://github.com/pytorch/pytorch/pull/65262
Reviewed By: mruberry
Differential Revision: D31037360
Pulled By: ngimel
fbshipit-source-id: 1c60f40c547229767cba3bbe7e11ca0fbbc8f95f
