Make index/rindex weak aliases of strchr/strrchr since they are not

part of the ISO C standard and have also been dropped from POSIX.
OK guenther@ kettenis@

src/lib/libc/string/index.c

@@ -1,43 +0,0 @@
-/*	$OpenBSD: index.c,v 1.6 2014/11/30 19:43:56 deraadt Exp $ */
-/*-
- * Copyright (c) 1990 The Regents of the University of California.
- * All rights reserved.
- *
- * 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.
- */
-
-#include <string.h>
-
-char *
-index(const char *p, int ch)
-{
-	for (;; ++p) {
-		if (*p == ch)
-			return((char *)p);
-		if (!*p)
-			return((char *)NULL);
-	}
-	/* NOTREACHED */
-}

src/lib/libc/string/rindex.c

@@ -1,45 +0,0 @@
-/*	$OpenBSD: rindex.c,v 1.7 2014/11/30 19:43:56 deraadt Exp $ */
-/*
- * Copyright (c) 1988 Regents of the University of California.
- * All rights reserved.
- *
- * 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.
- */
-
-#include <string.h>
-
-char *
-rindex(const char *p, int ch)
-{
-	char *save;
-
-	for (save = NULL;; ++p) {
-		if (*p == ch)
-			save = (char *)p;
-		if (!*p)
-			return(save);
-	}
-	/* NOTREACHED */
-}

src/lib/libc/string/strchr.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: strchr.c,v 1.1 2014/11/30 19:43:57 deraadt Exp $ */
+/*	$OpenBSD: strchr.c,v 1.2 2015/05/15 22:29:37 millert Exp $ */
 /*-
  * Copyright (c) 1990 The Regents of the University of California.
  * All rights reserved.
@@ -30,6 +30,8 @@
 
 #include <string.h>
 
+__weak_alias(index, strchr);
+
 char *
 strchr(const char *p, int ch)
 {

src/lib/libc/string/strrchr.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: strrchr.c,v 1.1 2014/11/30 19:43:57 deraadt Exp $ */
+/*	$OpenBSD: strrchr.c,v 1.2 2015/05/15 22:29:37 millert Exp $ */
 /*
  * Copyright (c) 1988 Regents of the University of California.
  * All rights reserved.
@@ -30,6 +30,8 @@
 
 #include <string.h>
 
+__weak_alias(rindex, strrchr);
+
 char *
 strrchr(const char *p, int ch)
 {