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/string/consttime_memequal.3

@@ -1,4 +1,4 @@
-.\"	$NetBSD: consttime_memequal.3,v 1.2 2013/08/28 15:24:41 riastradh Exp $
+.\"	$NetBSD: consttime_memequal.3,v 1.5 2015/03/23 07:41:16 apb Exp $
 .\"
 .\" Copyright (c) 2013 The NetBSD Foundation, Inc.
 .\" All rights reserved.
@@ -27,7 +27,7 @@
 .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 .\" POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd August 28, 2013
+.Dd March 23, 2015
 .Dt CONSTTIME_MEMEQUAL 3
 .Os
 .Sh NAME
@@ -48,8 +48,8 @@ bytes of memory at
 .Fa b1
 and
 .Fa b2
-for equality, returning zero if they are distinct and nonzero if they
-are identical.
+for equality, returning 0 if they are distinct and 1 if they are
+identical.
 .Pp
 The time taken by
 .Fn consttime_memequal
@@ -78,6 +78,13 @@ does not return a lexicographic ordering on the data at
 and
 .Fa b2 ;
 it tells only whether they are equal.
+.Nx
+does not provide a
+.Fn consttime_memcmp
+function, because all known use cases that require
+.Sq constant time
+memory comparison also require only comparison for equality,
+not lexicographic ordering.
 .Sh SEE ALSO
 .Xr explicit_memset 3 ,
 .Xr memcmp 3