Decouple forward AD checks from backward AD in OpInfo tests and gradcheck (#65040)
Summary:
Fixes https://github.com/pytorch/pytorch/issues/64999
- Adds a flag to gradcheck `check_backward_ad` that can be used to disable gradcheck for backward ad
- This is a bit bc-breaking in terms of positional args, but I prefer this ordering
- In OpInfo tests for forward ad:
- set `check_backward_ad` False
- In test_ops treat `supports_autograd` as if it is `supports_backward_ad` (it basically already is)
- the only modification needed is to no longer skip forward ad tests if `supports_autograd` is false
- test_dtype, test_variant_consistency, etc behave correctly as-is
- In a follow-up PR, we can rename it to actually be `supports_backward_ad`
- Testing
- https://github.com/pytorch/pytorch/pull/65060
Pull Request resolved: https://github.com/pytorch/pytorch/pull/65040
Reviewed By: albanD
Differential Revision: D31238177
Pulled By: soulitzer
fbshipit-source-id: f068d4cbe7ffb094930b16cddb210583b9b7b2c4
