[clang] [llvm] [HLSL] Implement dot2add intrinsic (PR #131237)

[Ashley Coleman via llvm-commits]

================
@@ -390,6 +390,18 @@ Value *CodeGenFunction::EmitHLSLBuiltinExpr(unsigned BuiltinID,
         getDotProductIntrinsic(CGM.getHLSLRuntime(), VecTy0->getElementType()),
         ArrayRef<Value *>{Op0, Op1}, nullptr, "hlsl.dot");
   }
+  case Builtin::BI__builtin_hlsl_dot2add: {
+    llvm::Triple::ArchType Arch = CGM.getTarget().getTriple().getArch();
+    assert(Arch == llvm::Triple::dxil && "Intrinsic dot2add can be executed as a builtin only on dxil");
----------------
V-FEXrt wrote:

nit:
```suggestion
    assert(Arch == llvm::Triple::dxil && "Intrinsic dot2add is only allowed for dxil architecture");
```

https://github.com/llvm/llvm-project/pull/131237