dont make alias for none value (#20112)
Summary:
Don't make an alias value for a value that is known to be None. This was preventing constant propagation from running the `out is None` check in nn.functional.normalize, and thus preventing the if statement from being inlined.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/20112
Differential Revision: D15267328
Pulled By: eellison
fbshipit-source-id: 5b878b0dc50944c2e7a2f583ea483dad9d6bbec3
