[clang] [HLSL] Put tests for compatibility overloads for 'clamp', 'isinf', 'min', and 'max' in own files (PR #137004)

[Finn Plummer via cfe-commits]

https://github.com/inbelic approved this pull request.

Can use the [NFC] tag as well if you want

https://github.com/llvm/llvm-project/pull/137004