[PyTorch] Add MaybeOwned::operator*() && (#55244)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/55244
Add the ability to move from the underlying object in a `MaybeOwned`.
FWIW, `MaybeOwned` is new territory for me personally and this move-and-dereference operation is even more so, but I think it makes sense and the tests pass.
ghstack-source-id: 126170046
Test Plan: Added automated tests.
Reviewed By: bhosmer
Differential Revision: D27522809
fbshipit-source-id: 82b180031e93d725209b6328f656315c232e5237
