Test TE fuser unary ops and fix sigmoid(half) (#44094)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/44094
Test Plan: Imported from OSS
Reviewed By: SplitInfinity
Differential Revision: D23494950
Pulled By: bertmaher
fbshipit-source-id: 676c4e57267c4ad92065ea90b06323918dd5b0de
