[ATen] Fix aten::to schema (#60001)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/60001
Fix the aten::to schema to reflect that the output may alias input.
Test Plan: Added new unit tests.
Reviewed By: ezyang
Differential Revision: D29121620
fbshipit-source-id: c29b6aa22d367ffedf06e47116bc46b3e188c39c
