[clang-tools-extra] [clang-doc][NFC] refactor out file helpers (PR #134298)

[Paul Kirth via cfe-commits]

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@@ -0,0 +1,25 @@
+//===-- File.h --- File Helpers -------------------*- C++-*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_DOC_FILEHELPER_H
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ilovepi wrote:

Macro name should match the file path. 

https://github.com/llvm/llvm-project/pull/134298