[clang] [llvm] [HLSL] [DXIL] Implement the `AddUint64` HLSL function and the `UAddc` DXIL op (PR #125319)

[Farzon Lotfi via cfe-commits]

================
@@ -10623,7 +10623,7 @@ def err_second_argument_to_cwsc_not_pointer : Error<
   "second argument to __builtin_call_with_static_chain must be of pointer type">;
 
 def err_vector_incorrect_num_elements : Error<
-  "%select{too many|too few}0 elements in vector %select{initialization|operand}3 (expected %1 elements, have %2)">;
+  "%select{too many|too few|incorrect number of}0 elements in vector %select{initialization|operand}3 (expected %1 elements, have %2)">;
----------------
farzonl wrote:

I don't like this change. this should stay being a diagnostic about the number of elements  but in SemaHLSL you are using it to say not a vector

your code:
```
if (!VTy) {
      SemaRef.Diag(TheCall->getBeginLoc(),
                   diag::err_vector_incorrect_num_elements)
```

https://github.com/llvm/llvm-project/pull/125319