Merge changes from gnulib. This was prompted because the CVS

snapshot of Bison didn't build on Solaris 7 due to strnlen problems.

m4/strnlen.m4

@@ -0,0 +1,32 @@
+# strnlen.m4 serial 2
+dnl Copyright (C) 2002-2003 Free Software Foundation, Inc.
+dnl This file is free software, distributed under the terms of the GNU
+dnl General Public License.  As a special exception to the GNU General
+dnl Public License, this file may be distributed as part of a program
+dnl that contains a configuration script generated by Autoconf, under
+dnl the same distribution terms as the rest of that program.
+
+AC_DEFUN([gl_FUNC_STRNLEN],
+[
+  dnl Persuade glibc <string.h> to declare strnlen().
+  AC_REQUIRE([AC_GNU_SOURCE])
+
+  AC_FUNC_STRNLEN
+  if test $ac_cv_func_strnlen_working = no; then
+    # This is necessary because automake-1.6.1 doens't understand
+    # that the above use of AC_FUNC_STRNLEN means we may have to use
+    # lib/strnlen.c.
+    #AC_LIBOBJ(strnlen)
+    AC_DEFINE(strnlen, rpl_strnlen,
+      [Define to rpl_strnlen if the replacement function should be used.])
+    gl_PREREQ_STRNLEN
+  fi
+])
+
+# Prerequisites of lib/strnlen.c.
+AC_DEFUN([gl_PREREQ_STRNLEN], [
+  AC_REQUIRE([AC_HEADER_STDC])
+  AC_CHECK_HEADERS_ONCE(memory.h string.h)
+  AC_CHECK_DECLS(memchr)
+])
+