[JIT] Fix AliasDB edge case for multi non existing alias sets in output (#81837)
- Although currently no ops have this form, it's possible to have an op of the form: op(Tensor a, Tensor b) -> Tensor(c | d)
Since the alias sets c and d both don't exist in the input arguments, the output should call createNewAlias(), however previously, this wasn't the case because it assumes that if there are two alias sets on an output, at least one will also exist in the input arguments which isn't necessarily the case.
- This is tested through all AliasDB tests passing in CI.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/81837
Approved by: https://github.com/davidberard98
