[clang] [HLSL] Implement the SV_InstanceID semantic (PR #221091)

[Gregory Roth via cfe-commits]

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@@ -1111,6 +1114,12 @@ void SemaHLSL::checkSemanticAnnotation(
     return;
   }
 
+  if (SemanticName == "SV_INSTANCEID") {
+    diagnoseSemanticStageMismatch(SemanticAttr, ST, SC.CurrentIOType,
+                                  {{llvm::Triple::Vertex, IOType::In}});
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pow2clk wrote:

Disregard. While DXC allows this usage in PS, it's really just treating it like a user-defined semantic

https://github.com/llvm/llvm-project/pull/221091