mkstemps was added in GLIBC-2.11 (http://sourceware.org/git/?p=glibc.git;a=commitdiff;h=3a83202db6e5591f2b72974c1ad98602c6620770)
Pretend not to have it (even on systems with GLIBC >= 2.11) and use the bundled version of it instead in order to avoid the dependency on GLIBC-2.11

--- libiberty/configure
+++ libiberty/configure
@@ -5356,7 +5356,7 @@
 funcs="$funcs memmove"
 funcs="$funcs mempcpy"
 funcs="$funcs memset"
-funcs="$funcs mkstemps"
+funcs="$funcs mkstemps"; ac_cv_func_mkstemps=no
 funcs="$funcs putenv"
 funcs="$funcs random"
 funcs="$funcs rename"
--- libiberty/make-temp-file.c
+++ libiberty/make-temp-file.c
@@ -48,7 +48,7 @@
 #endif
 
 #include "libiberty.h"
-extern int mkstemps (char *, int);
+extern int mkstemps_libiberty (char *, int);
 
 /* '/' works just fine on MS-DOS based systems.  */
 #ifndef DIR_SEPARATOR
@@ -202,7 +202,7 @@
   strcpy (temp_filename + base_len, TEMP_FILE);
   strcpy (temp_filename + base_len + TEMP_FILE_LEN, suffix);
 
-  fd = mkstemps (temp_filename, suffix_len);
+  fd = mkstemps_libiberty (temp_filename, suffix_len);
   /* Mkstemps failed.  It may be EPERM, ENOSPC etc.  */
   if (fd == -1)
     {
--- libiberty/mkstemps.c
+++ libiberty/mkstemps.c
@@ -55,7 +55,7 @@
 
 /*
 
-@deftypefn Replacement int mkstemps (char *@var{pattern}, int @var{suffix_len})
+@deftypefn Replacement int mkstemps_libiberty (char *@var{pattern}, int @var{suffix_len})
 
 Generate a unique temporary file name from @var{pattern}.
 @var{pattern} has the form:
@@ -75,7 +75,7 @@
 */
 
 int
-mkstemps (char *pattern, int suffix_len)
+mkstemps_libiberty (char *pattern, int suffix_len)
 {
   static const char letters[]
     = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
--- libiberty/pex-common.c
+++ libiberty/pex-common.c
@@ -37,7 +37,7 @@
 #include <unistd.h>
 #endif
 
-extern int mkstemps (char *, int);
+extern int mkstemps_libiberty (char *, int);
 
 /* This file contains subroutines for the program execution routines
    (pex_init, pex_run, etc.).  This file is compiled on all
@@ -119,7 +119,7 @@
           else
             name = concat (obj->tempbase, "XXXXXX", NULL);
 
-          out = mkstemps (name, 0);
+          out = mkstemps_libiberty (name, 0);
           if (out < 0)
             {
               free (name);