pytorch

7c72bc48 - Add mechanism to disable the "saved tensors hooks" feature (#85971)

Add mechanism to disable the "saved tensors hooks" feature (#85971) The rationale for this is that functorch doesn't work with saved variable hooks at the moment or checkpointing and we need some way to disable it. Concretely: - there's a context manager that does the disabling - this feature is disabled on a thread-local basis - one can set an error message or use the default error message that says the feature has been disabled Since it is thread local I needed to update ATen/ThreadLocalState. To make things nicer, this PR refactors all the "saved tensors hooks" related TLS things into a single struct. Test Plan: - new test Differential Revision: [D39970936](https://our.internmc.facebook.com/intern/diff/D39970936) Pull Request resolved: https://github.com/pytorch/pytorch/pull/85971 Approved by: https://github.com/albanD, https://github.com/soulitzer