[clang-tools-extra] [clang-tidy] Preserve comments in `readability-use-std-min-max` (PR #169908)

[via cfe-commits]

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@@ -172,13 +172,52 @@ void UseStdMinMaxCheck::check(const MatchFinder::MatchResult &Result) {
 
   auto ReplaceAndDiagnose = [&](const llvm::StringRef FunctionName) {
     const SourceManager &Source = *Result.SourceManager;
+    llvm::SmallString<64> Comment;
+
+    const auto AppendNormalized = [&](llvm::StringRef Text) {
+      Text = Text.ltrim();
+      if (!Text.empty()) {
+        if (!Comment.empty())
+          Comment += " ";
+        Comment += Text;
+      }
+    };
+
+    AppendNormalized(Lexer::getSourceText(
+        CharSourceRange::getCharRange(
+            Lexer::getLocForEndOfToken(If->getRParenLoc(), 0, Source, LO),
+            If->getThen()->getBeginLoc()),
+        Source, LO));
+
+    if (const auto *CS = dyn_cast<CompoundStmt>(If->getThen())) {
+      const Stmt *Inner = CS->body_front();
+      AppendNormalized(Lexer::getSourceText(
+          CharSourceRange::getCharRange(
+              Lexer::getLocForEndOfToken(CS->getBeginLoc(), 0, Source, LO),
+              Inner->getBeginLoc()),
+          Source, LO));
+
+      llvm::StringRef PostInner = Lexer::getSourceText(
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zeyi2 wrote:

Captures:
- `if (cond) { x = y; // Comment C`
- `if (cond) { x = y; /* Comment C */ }`

It also strip the trailing `;`

https://github.com/llvm/llvm-project/pull/169908