[optests] Add dontGenerateOpCheckTests and is_inside_opcheck_mode (#110951)
This PR adds the following helper functions for generated opcheck tests:
- dontGenerateOpCheckTests is a decorator that skips generation of the
opcheck tests for the generated function
- is_inside_opcheck_mode lets us query if we are in a generated test.
Useful for fast debugging out-of-tree without needing to update
PyTorch.
Test Plan:
- new tests
Pull Request resolved: https://github.com/pytorch/pytorch/pull/110951
Approved by: https://github.com/williamwen42
