[clang] [clang-format] Add an fnmatch-like function for .clang-format-ignore (PR #76021)

[Owen Pan via cfe-commits]

================
@@ -0,0 +1,121 @@
+//===--- MatchFilePath.cpp - Match file path with pattern -------*- 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
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// This file implements the functionality of matching a file path name to
+/// a pattern, similar to the POSIX fnmatch() function.
+///
+//===----------------------------------------------------------------------===//
+
+#include "MatchFilePath.h"
+
+using namespace llvm;
+
+namespace clang {
+namespace format {
+
+// Check whether `FilePath` matches `Pattern` based on POSIX Section 2.13.
----------------
owenca wrote:

```suggestion
// Check whether `FilePath` matches `Pattern` based on POSIX (1003.1-2008)
// 2.13.1, 2.13.2, and Rule 1 of 2.13.3.
```

https://github.com/llvm/llvm-project/pull/76021