Use easy way to sense C and POSIX locales, like in GLIBC

contrib/gnu-sort/lib/hard-locale.c

@@ -14,6 +14,7 @@
    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software Foundation,
    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+/* $FreeBSD$ */
 
 #if HAVE_CONFIG_H
 # include <config.h>
@@ -62,7 +63,7 @@ hard_locale (int category)
 
   if (p)
     {
-# if defined __GLIBC__ && __GLIBC__ >= 2
+# if defined(__FreeBSD__) || (defined __GLIBC__ && __GLIBC__ >= 2)
       if (strcmp (p, "C") == 0 || strcmp (p, "POSIX") == 0)
 	hard = 0;
 # else