Support operator list in LightWeightDispatch
Pull Request resolved: https://github.com/pytorch/pytorch/pull/76699
Support selecting operators from a static ops list in codegen_unboxing for lightweight dispatch, like supported in gen.py
Differential Revision: [D36017218](https://our.internmc.facebook.com/intern/diff/D36017218/)
**NOTE FOR REVIEWERS**: This PR has internal Facebook specific changes or comments, please review them on [Phabricator](https://our.internmc.facebook.com/intern/diff/D36017218/)!
Approved by: https://github.com/larryliu0820
