Add strnlen() replacement needed for glob.c.

Only used if no glob() and no strnlen().

configure

@@ -18930,6 +18930,32 @@ esac
 "
     done
 
+    for ac_func in strnlen
+do :
+  ac_fn_c_check_func "$LINENO" "strnlen" "ac_cv_func_strnlen"
+if test "x$ac_cv_func_strnlen" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_STRNLEN 1
+_ACEOF
+
+else
+
+	case " $LIBOBJS " in
+  *" strnlen.$ac_objext "* ) ;;
+  *) LIBOBJS="$LIBOBJS strnlen.$ac_objext"
+ ;;
+esac
+
+
+    for _sym in sudo_strnlen; do
+	COMPAT_EXP="${COMPAT_EXP}${_sym}
+"
+    done
+
+
+fi
+done
+
 
 fi
 done