Fallback support for more operators (#16456)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/16456
Adding fallbacks for more operators and fixing ifndef for expand_op.h
Reviewed By: yinghai
Differential Revision: D13845382
fbshipit-source-id: b7c5b7f7f176707b9ddffade139562a8085967ed
