Kill CPPTypeToScalarType. It's now subsumed by CPPTypeAndStdComplexToScalarType. (#39263)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/39263
CPPTypeToScalarType is confusing because it doesn't handle the different complex types and it maps everything that it doesn't know about to Undefined, which is error prone.
Test Plan: Imported from OSS
Differential Revision: D21790515
Pulled By: gchanan
fbshipit-source-id: ec897fd50bd8f7548a34573e59eb57bf3c6383c6
