[JIT] Constant prop getattr (#49806)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/49806
Fix for https://github.com/pytorch/pytorch/issues/47089
Test Plan: Imported from OSS
Reviewed By: navahgar
Differential Revision: D25696791
Pulled By: eellison
fbshipit-source-id: 914c17b8effef7f4f341775ac2b8150ee4703efd
