Remove call_unboxed_super_slow_temp_shim (#38351)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/38351
ghstack-source-id: 104368838
Test Plan: waitforsandcastle
Differential Revision: D21530545
fbshipit-source-id: cdfb801e551993ecb339f3f8ec7c9b3039766989
