NetBSD re-synchronization of the source tree

This brings our tree to NetBSD 7.0, as found on -current on the
10-10-2015.

This updates:
 - LLVM to 3.6.1
 - GCC to GCC 5.1
 - Replace minix/commands/zdump with usr.bin/zdump
 - external/bsd/libelf has moved to /external/bsd/elftoolchain/
 - Import ctwm
 - Drop sprintf from libminc

Change-Id: I149836ac18e9326be9353958bab9b266efb056f0

lib/libc/stdlib/pty.c

@@ -1,4 +1,4 @@
-/*	$NetBSD: pty.c,v 1.2 2008/04/28 20:23:00 martin Exp $	*/
+/*	$NetBSD: pty.c,v 1.4 2014/01/08 02:17:30 christos Exp $	*/
 
 /*-
  * Copyright (c) 2004 The NetBSD Foundation, Inc.
@@ -31,11 +31,13 @@
 
 #include <sys/cdefs.h>
 #if defined(LIBC_SCCS) && !defined(lint)
-__RCSID("$NetBSD: pty.c,v 1.2 2008/04/28 20:23:00 martin Exp $");
+__RCSID("$NetBSD: pty.c,v 1.4 2014/01/08 02:17:30 christos Exp $");
 #endif /* LIBC_SCCS and not lint */
 
 #include "namespace.h"
 #include <fcntl.h>
+#include <string.h>
+#include <errno.h>
 #include <stdlib.h>
 #include <sys/ioctl.h>
 
@@ -64,3 +66,16 @@ ptsname(int fildes)
 
 	return pm.sn;
 }
+
+int
+ptsname_r(int fildes, char *buf, size_t buflen) {
+	struct ptmget pm;
+
+	if (buf == NULL)
+		return EINVAL;
+	if (ioctl(fildes, TIOCPTSNAME, &pm) == -1)
+		return errno;
+	if (strlcpy(buf, pm.sn, buflen) > buflen)
+		return ERANGE;
+	return 0;
+}