New additions/bug fixes required/found when porting perf.

New functions:
	tfind
	tsearch
	tdelete
	twalk
	tdestroy (GNU extension)

Bug fix: the current implementation for realpath would crash
	if the second argument (resolved_path) is NULL.

New headers:
	ar.h
	search.h

Change-Id: Ib6c1e42fc186a6d597a6e5a9692b16acaa155804
diff --git a/libc/include/ar.h b/libc/include/ar.h
new file mode 100644
index 0000000..835290b
--- /dev/null
+++ b/libc/include/ar.h
@@ -0,0 +1,66 @@
+/*	$OpenBSD: ar.h,v 1.3 2003/06/02 19:34:12 millert Exp $	*/
+/*	$NetBSD: ar.h,v 1.4 1994/10/26 00:55:43 cgd Exp $	*/
+
+/*-
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * (c) UNIX System Laboratories, Inc.
+ * All or some portions of this file are derived from material licensed
+ * to the University of California by American Telephone and Telegraph
+ * Co. or Unix System Laboratories, Inc. and are reproduced herein with
+ * the permission of UNIX System Laboratories, Inc.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Hugh Smith at The University of Guelph.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)ar.h	8.2 (Berkeley) 1/21/94
+ */
+
+#ifndef _AR_H_
+#define	_AR_H_
+
+/* Pre-4BSD archives had these magic numbers in them. */
+#define	OARMAG1	0177555
+#define	OARMAG2	0177545
+
+#define	ARMAG		"!<arch>\n"	/* ar "magic number" */
+#define	SARMAG		8		/* strlen(ARMAG); */
+
+#define	AR_EFMT1	"#1/"		/* extended format #1 */
+
+struct ar_hdr {
+	char ar_name[16];		/* name */
+	char ar_date[12];		/* modification time */
+	char ar_uid[6];			/* user id */
+	char ar_gid[6];			/* group id */
+	char ar_mode[8];		/* octal file permissions */
+	char ar_size[10];		/* size in bytes */
+#define	ARFMAG	"`\n"
+	char ar_fmag[2];		/* consistency check */
+};
+
+#endif /* !_AR_H_ */
diff --git a/libc/include/search.h b/libc/include/search.h
new file mode 100644
index 0000000..ed0d216
--- /dev/null
+++ b/libc/include/search.h
@@ -0,0 +1,46 @@
+/*-
+ * Written by J.T. Conklin <jtc@netbsd.org>
+ * Public domain.
+ *
+ *	$NetBSD: search.h,v 1.12 1999/02/22 10:34:28 christos Exp $
+ * $FreeBSD: release/9.0.0/include/search.h 105250 2002-10-16 14:29:23Z robert $
+ */
+
+#ifndef _SEARCH_H_
+#define _SEARCH_H_
+
+#include <sys/cdefs.h>
+#include <sys/_types.h>
+
+#if 0
+#ifndef _SIZE_T_DECLARED
+typedef	__size_t	size_t;
+#define	_SIZE_T_DECLARED
+#endif
+#endif
+
+typedef	enum {
+	preorder,
+	postorder,
+	endorder,
+	leaf
+} VISIT;
+
+#ifdef _SEARCH_PRIVATE
+typedef	struct node {
+	char         *key;
+	struct node  *llink, *rlink;
+} node_t;
+#endif
+
+__BEGIN_DECLS
+void	*tdelete(const void * __restrict, void ** __restrict,
+	    int (*)(const void *, const void *));
+void	*tfind(const void *, void * const *,
+	    int (*)(const void *, const void *));
+void	*tsearch(const void *, void **, int (*)(const void *, const void *));
+void	 twalk(const void *, void (*)(const void *, VISIT, int));
+void	 tdestroy(void *, void (*)(void *));
+__END_DECLS
+
+#endif /* !_SEARCH_H_ */