[OpenMP] Make CUDA math library functions SPMD amenable

This patch adds the SPMD amenable assumption to the CUDA math library
defintions in Clang. Previously these functions would block SPMD
execution on the device because they're intrinsic calls into the library
and can't be calculated. These functions don't have side-effects so they
are safe to execute in SPMD mode.

Depends on D105937

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D108958