Backport of the addition of
      sysdeps/powerpc/powerpc64/multiarch/strncat-power7.c
    from the following:
    
    commit 9f2f36e5a91c2ce6edba5415e176155eb1008ae1
    Author: Adhemerval Zanella <azanella@linux.vnet.ibm.com>
    Date:   Tue Dec 23 13:39:23 2014 -0500
    
        powerpc: Optimized strncat for POWER7/PPC64
    
        With 3eb38795dbbbd816 (Simplify strncat) the generic algorithms uses
        strlen, strnlen, and memcpy.  This is faster than POWER7 current
        implementation, especially for unaligned strings (where POWER7 code
        uses byte-byte operations).
    
        This patch removes the assembly implementation and uses a multiarch
        specialization based on default algorithm calling optimized POWER7
        symbols.
    
        ChangeLog:
            2015-01-13  Adhemerval Zanella  <azanella@linux.vnet.ibm.com>
    
            * sysdeps/powerpc/powerpc64/multiarch/strncat-power7.c: New file.
            * sysdeps/powerpc/powerpc64/multiarch/strncat-power7.S: Remove file.
            * sysdeps/powerpc/powerpc64/power7/strncat.S: Likewise.
    
    plus the addition of strncat-power7 to
      sysdeps/powerpc/powerpc64/multiarch/Makefile

diff --git a/sysdeps/powerpc/powerpc64/multiarch/Makefile b/sysdeps/powerpc/powerpc64/multiarch/Makefile
index 7ebfc7e..74ae710 100644
--- a/sysdeps/powerpc/powerpc64/multiarch/Makefile
+++ b/sysdeps/powerpc/powerpc64/multiarch/Makefile
@@ -8,6 +8,7 @@ sysdep_routines += memcpy-power7 memcpy-a2 memcpy-power6 memcpy-cell \
                   stpcpy-power8 stpcpy-power7 stpcpy-ppc64 \
                   strcat-power8 strcat-power7 strcat-ppc64 \
                   strcpy-power8 strcpy-power7 strcpy-ppc64 \
+                  strncat-power7 \
                   rawmemchr-ppc64 strlen-power7 strlen-ppc64 strnlen-power7 \
                   strnlen-ppc64 strcasecmp-power7 strcasecmp_l-power7 \
                   strncase-power7 strncase_l-power7 strncmp-power7 \
diff --git a/sysdeps/powerpc/powerpc64/multiarch/strncat-power7.c b/sysdeps/powerpc/powerpc64/multiarch/strncat-power7.c
new file mode 100644
index 0000000..39b1aeb
--- /dev/null
+++ b/sysdeps/powerpc/powerpc64/multiarch/strncat-power7.c
@@ -0,0 +1,31 @@
+/* Copyright (C) 2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/ >.  */
+
+#include <string.h>
+
+#define STRNCAT __strncat_power7
+
+extern __typeof (strncat) __strncat_power7 attribute_hidden;
+extern __typeof (strlen) __strlen_power7 attribute_hidden;
+extern __typeof (strnlen) __strnlen_power7 attribute_hidden;
+extern __typeof (memcpy) __memcpy_power7 attribute_hidden;
+
+#define strlen    __strlen_power7
+#define __strnlen __strnlen_power7
+#define memcpy    __memcpy_power7
+
+#include <string/strncat.c>