[clang] [HLSL] Implementation of the elementwise fmod builtin (PR #108849)

[Zhengxing li via cfe-commits]

lizhengxing wrote:

> change the title of this PR to remove the word intrinsic. That word has a specific meaning in LLVM and folks might get confused. Something like: `[HLSL] Implementation of the fmod API`.
> 
> If you really want to use the word intrinsic then just reuse the HLSL keyword so HLSL is a modifier to specify the kind of intrinsic: `[HLSL] Implementation of the fmod HLSL intrinsic`.

Done. Renamed it to `[HLSL] Implementation of the elementwise fmod builtin` .

https://github.com/llvm/llvm-project/pull/108849