[clang] [HLSL] Vector standard conversions (PR #71098)

[Aaron Ballman via cfe-commits]

================
@@ -4739,6 +4753,76 @@ Sema::PerformImplicitConversion(Expr *From, QualType ToType,
     llvm_unreachable("Improper second standard conversion");
   }
 
+  if (SCS.Element != ICK_Identity) {
+    // if SCS.Element is not ICK_Identity the To and From types must be HLSL
----------------
AaronBallman wrote:

```suggestion
    // If SCS.Element is not ICK_Identity the To and From types must be HLSL
```

https://github.com/llvm/llvm-project/pull/71098