[clang] [HLSL] Implement support for HLSL intrinsic - select (PR #107129)

[Damyan Pepper via cfe-commits]

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@@ -1544,6 +1604,30 @@ bool SemaHLSL::CheckBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
       return true;
     break;
   }
+  case Builtin::BI__builtin_hlsl_select: {
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damyanp wrote:

This implementation has quite a different shape to the other builtins in this function.  I'm trying to figure out if there's something special about `select` that makes this necessary, or if this validation can be expressed using the existing CheckXXX functions in here.

https://github.com/llvm/llvm-project/pull/107129