Remove generic_if.h. (#16354)
Summary:
The current uses of `IR_IF` are mostly trivial, so there is not much value in having special macros for it.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/16354
Differential Revision: D13821823
Pulled By: ZolotukhinM
fbshipit-source-id: 1ca73111f5b4868fa38a1f29c9230540773e5de6
Author
Mikhail Zolotukhin
