Remove most usages of THCHalfAutoNumerics. (#21878)
Summary:
This was originally introduced between at::Half, which overloaded a number of operators; since this isn't necessary anymore, get rid of it.
Note in many cases, these files still need THCNumerics.cuh (which was included by THCHalfAutoNumerics); I was not careful about isolating these usages.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/21878
Differential Revision: D15941236
Pulled By: gchanan
fbshipit-source-id: 65f30a20089fcd618e8f3e9646cf03147a15ccba
