Migrate CUDA where, tril, triu to c10::complex (#37896)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/37896
Test Plan: Imported from OSS
Differential Revision: D21442150
Pulled By: anjali411
fbshipit-source-id: b80ff801572a61f76dd25f94726a2a6334a89f3b
