[clang] [clang][CUDA] Define _NV_RSQRT_SPECIFIER for glibc-2.42/cuda-13.2 compatibility (PR #185701)

[Corentin Kerisit via cfe-commits]

cerisier wrote:

Thanks for taking care of that, out of curiosity, why isn't `math_functions.h` no included by clang ?
Also, will this patch make it in a 22.1.1 patch ?

https://github.com/llvm/llvm-project/pull/185701