[clang] [llvm] [clang][NVPTX] Add overloaded fmul intrinsics (PR #224546)

[Durgadoss R via llvm-commits]

durga4github wrote:

Now that the 13.4 docs are out, let us refer to them instead of the developer-preview docs in the commit message.

https://github.com/llvm/llvm-project/pull/224546