[clang-tools-extra] [clang-tidy] [NFC] Move comment scanning to `LexerUtils` and add tests (PR #180371)

[Baranov Victor via cfe-commits]

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@@ -0,0 +1,130 @@
+//===--- LexerUtilsTest.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 "../clang-tidy/utils/LexerUtils.h"
+
+#include "clang/Basic/FileManager.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Frontend/ASTUnit.h"
+#include "clang/Serialization/PCHContainerOperations.h"
+#include "clang/Tooling/Tooling.h"
+#include "llvm/Support/Error.h"
+#include "llvm/Testing/Annotations/Annotations.h"
+#include "gtest/gtest.h"
+
+namespace clang {
+namespace tidy {
+namespace test {
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vbvictor wrote:

```suggestion
namespace clang::tidy::test {
```

https://github.com/llvm/llvm-project/pull/180371