[clang] [clang] Introduce `SemaHLSL` (PR #87912)

[Vlad Serebrennikov via cfe-commits]

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@@ -1967,6 +1973,11 @@ class Sema final : public SemaBase {
   bool CheckFunctionCall(FunctionDecl *FDecl, CallExpr *TheCall,
                          const FunctionProtoType *Proto);
 
+  bool BuiltinVectorMath(CallExpr *TheCall, QualType &Res);
+  bool BuiltinVectorToScalarMath(CallExpr *TheCall);
+
+  bool CheckHLSLBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall);
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Endilll wrote:

I tried, but it depends on a lot of static functions inside `SemaChecking.cpp`, so I decided to leave it for later.

https://github.com/llvm/llvm-project/pull/87912