nfc: remove unused diag reporting

Author: inbelic

clang/include/clang/Parse/ParseHLSLRootSignature.h

@@ -197,11 +197,8 @@ class RootSignatureParser {
   /// StringLiterals
   SourceLocation getTokenLocation(RootSignatureToken Tok);
 
-  DiagnosticBuilder
-  reportDiag(unsigned DiagID,
-             std::optional<RootSignatureToken> Context = std::nullopt) {
-    RootSignatureToken Tok = Context.has_value() ? *Context : CurToken;
-    return getDiags().Report(getTokenLocation(Tok), DiagID);
+  DiagnosticBuilder reportDiag(unsigned DiagID) {
+    return getDiags().Report(getTokenLocation(CurToken), DiagID);
   }
 
 private: