Fixes for some Windows compiler warnings (#14490)
Summary:
Implement some simple fixes to clean up windows build by fixing compiler warnings. Three main types of warnings were fixes:
1. GCC specific pragmas were changed to not be used on windows.
2. cmake flags that don't exist on windows were removed from windows build
3. Fix a macro that was defined multiple times on Windows.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/14490
Differential Revision:
D13241988
Pulled By: ezyang
fbshipit-source-id:
38da8354f0e3a3b9c97e33309cdda9fd23c08247