[clang-tools-extra] [clang-tidy][NFC] Clean up and slightly optimize `modernize-use-integer-sign-comparison` (PR #163492)

[Victor Chernyakin via cfe-commits]

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@@ -156,21 +147,21 @@ void UseIntegerSignComparisonCheck::check(
   DiagnosticBuilder Diag =
       diag(BinaryOp->getBeginLoc(),
            "comparison between 'signed' and 'unsigned' integers");
-  std::string CmpNamespace;
-  llvm::StringRef CmpHeader;
+  StringRef CmpNamespace;
+  StringRef CmpHeader;
 
   if (getLangOpts().CPlusPlus20) {
     CmpHeader = "<utility>";
-    CmpNamespace = llvm::Twine("std::" + parseOpCode(OpCode)).str();
+    CmpNamespace = "std::";
   } else if (getLangOpts().CPlusPlus17 && EnableQtSupport) {
     CmpHeader = "<QtCore/q20utility.h>";
-    CmpNamespace = llvm::Twine("q20::" + parseOpCode(OpCode)).str();
+    CmpNamespace = "q20::";
   }
 
   // Prefer modernize-use-integer-sign-comparison when C++20 is available!
   Diag << FixItHint::CreateReplacement(
       CharSourceRange(R1, SubExprLHS != nullptr),
-      llvm::Twine(CmpNamespace + "(").str());
+      Twine(CmpNamespace + parseOpCode(BinaryOp->getOpcode()) + "(").str());
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localspook wrote:

Moving the `parseOpCode()` call down here removes the duplication above

https://github.com/llvm/llvm-project/pull/163492