move basic math ops to lite interpreter (#39861)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/39861
move some basic math ops to lite interpreter
size change should be small
Test Plan: build
Reviewed By: iseeyuan
Differential Revision: D21992552
fbshipit-source-id: 7f5a7380ffc1519001a98169e6c5381e45e8e0ea
