[libclc] libclc: Replace fmod implementation with elementwise builtin (PR #186083)

[Romaric Jodin via cfe-commits]

rjodinchr wrote:

This change is breaking `fmod` on some platforms using `clspv`. I'm not sure to understand where the fmod implementation should be coming from if not from libclc. Is it part of LLVM? I don't see it, but I might have missed it.

https://github.com/llvm/llvm-project/pull/186083