Provide a generic empty version of __check_native.

Add an empty implementation of __check_native, as used in the posix version of getaddrinfo.
This allows non-Linux GNU-based OSes to compile.

2012-07-26  Pino Toscano  <toscano.pino@tiscali.it>

	* inet/check_native.c: New file.
--- /dev/null
+++ b/inet/check_native.c
@@ -0,0 +1,27 @@
+/* Determine whether interfaces use native transport.  Generic version.
+   Copyright (C) 2012 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 <ifaddrs.h>
+
+
+void
+attribute_hidden
+__check_native (uint32_t a1_index, int *a1_native,
+		uint32_t a2_index, int *a2_native)
+{
+}