[clang] [llvm] [HLSL] implement `mad` intrinsic (PR #83826)

[Xiang Li via cfe-commits]

================
@@ -31,4 +31,8 @@ def int_dx_lerp :
     Intrinsic<[LLVMScalarOrSameVectorWidth<0, LLVMVectorElementType<0>>],
     [llvm_anyvector_ty, LLVMScalarOrSameVectorWidth<0, LLVMVectorElementType<0>>,LLVMScalarOrSameVectorWidth<0, LLVMVectorElementType<0>>],
     [IntrNoMem, IntrWillReturn] >;
+
+
----------------
python3kgae wrote:

```suggestion

```

https://github.com/llvm/llvm-project/pull/83826