Support operations on c10::complex and integer scalars (#38418)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/38418
This is useful in reducing verbosity in c10::complex's general usage, and potentially also offers
performance benefits.
This brings back #34506 (which was made for std::complex).
Differential Revision: D21587012
Test Plan: Imported from OSS
Pulled By: malfet
fbshipit-source-id: 6dd10c2f417d6f6d0935c9e1d8b457fd29c163af
