Better THGeneric.h generation rules in bazel (#41285)
Summary:
It doesn't do a good job of checking BLAS library capabilities, so hardcode the undef of BLAS_F2C
Pull Request resolved: https://github.com/pytorch/pytorch/pull/41285
Differential Revision: D22489781
Pulled By: malfet
fbshipit-source-id: 13a14f31e08d7f9ded49731e4fd23663bac75cd2
