From b86c249691a7973a451bc6a586b39da64778d219 Mon Sep 17 00:00:00 2001
From: Hans Wennborg <hans@chromium.org>
Date: Mon, 8 May 2023 15:51:52 +0200
Subject: [PATCH] Use LLVM-style include guard in regex_impl.h

The previous include guard (_REGEX_H_) is also used in a macOS SDK
header (xlocale.h), causing potential for trouble. This was previously
addressed in 2b8b90a7686858b1d22cae6fcfbd0904135112aa, but renaming the
macro in line with LLVM's other include guards seems like a better fix.

Differential revision: https://reviews.llvm.org/D150117
--- a/lib/Support/regex_impl.h
+++ b/lib/Support/regex_impl.h
@@ -35,8 +35,8 @@
  *	@(#)regex.h	8.1 (Berkeley) 6/2/93
  */
 
-#ifndef _REGEX_H_
-#define	_REGEX_H_
+#ifndef LLVM_SUPPORT_REGEX_IMPL_H
+#define LLVM_SUPPORT_REGEX_IMPL_H
 
 #include <sys/types.h>
 typedef off_t llvm_regoff_t;
@@ -105,4 +105,4 @@ size_t  llvm_strlcpy(char *dst, const char *src, size_t siz);
 }
 #endif
 
-#endif /* !_REGEX_H_ */
+#endif /* LLVM_SUPPORT_REGEX_IMPL_H */