libroot: Replace ftw/nftw implemenations with their musl counterparts.

Rewrite ftw.h to be a Haiku header instead of a BSD one while at it.

headers/posix/ftw.h

@@ -1,63 +1,44 @@
-/*	$OpenBSD: ftw.h,v 1.1 2003/07/21 21:13:18 millert Exp $	*/
-
 /*
- * Copyright (c) 2003 Todd C. Miller <[email protected]>
- *
- * Permission to use, copy, modify, and distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
- * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
- * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
- * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
- *
- * Sponsored in part by the Defense Advanced Research Projects
- * Agency (DARPA) and Air Force Research Laboratory, Air Force
- * Materiel Command, USAF, under agreement number F39502-99-1-0512.
- *
- * $FreeBSD$
+ * Copyright 2022, Haiku, Inc. All rights reserved.
+ * Distributed under the terms of the MIT License.
  */
+#ifndef	_FTW_H_
+#define	_FTW_H_
 
-#ifndef	_FTW_H
-#define	_FTW_H
 
-#include <sys/cdefs.h>
-#include <sys/types.h>
+#include <features.h>
 #include <sys/stat.h>
 
-/*
- * Valid flags for the 3rd argument to the function that is passed as the
- * second argument to ftw(3) and nftw(3).  Say it three times fast!
- */
-#define	FTW_F		0	/* File.  */
-#define	FTW_D		1	/* Directory.  */
-#define	FTW_DNR		2	/* Directory without read permission.  */
-#define	FTW_DP		3	/* Directory with subdirectories visited.  */
-#define	FTW_NS		4	/* Unknown type; stat() failed.  */
-#define	FTW_SL		5	/* Symbolic link.  */
-#define	FTW_SLN		6	/* Sym link that names a nonexistent file.  */
 
-/*
- * Flags for use as the 4th argument to nftw(3).  These may be ORed together.
- */
-#define	FTW_PHYS	0x01	/* Physical walk, don't follow sym links.  */
-#define	FTW_MOUNT	0x02	/* The walk does not cross a mount point.  */
-#define	FTW_DEPTH	0x04	/* Subdirs visited before the dir itself. */
-#define	FTW_CHDIR	0x08	/* Change to a directory before reading it. */
+#define	FTW_F		0
+#define	FTW_D		1
+#define	FTW_DNR		2
+#define	FTW_DP		3
+#define	FTW_NS		4
+#define	FTW_SL		5
+#define	FTW_SLN		6
+
+#define	FTW_PHYS	0x01
+#define	FTW_MOUNT	0x02
+#define	FTW_DEPTH	0x04
+#define	FTW_CHDIR	0x08
 
 struct FTW {
 	int base;
 	int level;
 };
 
-__BEGIN_DECLS
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 int	ftw(const char *, int (*)(const char *, const struct stat *, int), int);
 int	nftw(const char *, int (*)(const char *, const struct stat *, int,
-	    struct FTW *), int, int);
-__END_DECLS
+	struct FTW *), int, int);
 
-#endif	/* !_FTW_H */
+#ifdef __cplusplus
+}
+#endif
+
+#endif	/* _FTW_H_ */