[clang] [HLSL] prevent generation of double intrinsics. (PR #86932)

[Farzon Lotfi via cfe-commits]

farzonl wrote:

So keep in mind there are some double cases that are valid for hlsl. so always check via dxc  which can be easily used via [hlsl.godbolt](https://hlsl.godbolt.org/).

https://github.com/llvm/llvm-project/pull/86932