[clang-tools-extra] [tidy] add new check bugprone-return-const-ref-from-parameter (PR #89497)

[Danny Mösch via cfe-commits]

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@@ -0,0 +1,41 @@
+//===--- ReturnConstRefFromParameterCheck.cpp - clang-tidy ----------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "ReturnConstRefFromParameterCheck.h"
+#include "../utils/Matchers.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
+
+using namespace clang::ast_matchers;
+
+namespace clang::tidy::bugprone {
+
+std::optional<TraversalKind>
+ReturnConstRefFromParameterCheck::getCheckTraversalKind() const {
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SimplyDanny wrote:

I always wonder where these little methods are supposed to be implemented. Wondering because the implementation for `isLanguageVersionSupported` is also in the header file.

https://github.com/llvm/llvm-project/pull/89497