Fix enum constant printing and add FileCheck to all Enum tests (#42874)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/42874
Test Plan: Imported from OSS
Reviewed By: SplitInfinity
Differential Revision: D23222894
Pulled By: gmagogsfm
fbshipit-source-id: 86495a350d388c82276933d24a2ca3c0f59af8da
