Delete all unnecessary singular Math entries (#54436)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/54436
An operator entry with no dispatch table implicitly generates a Math
entry, so you don't need to define one yourself. I also added
some asserts in the codegen to fail on these cases.
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Test Plan: Imported from OSS
Reviewed By: ailzhang
Differential Revision: D27235381
Pulled By: ezyang
fbshipit-source-id: f8c905090b863120f4f3656c37e2b7f26e8bb9ef
