* fhandler_socket.cc (fhandler_socket::ioctl): Handle SIOCGIFINDEX.

	* fhandler_socket.cc (fhandler_socket::ioctl): Handle SIOCGIFINDEX.
	* net.cc (get_2k_ifconf): Ditto.
	(get_nt_ifconf): Fake SIOCGIFINDEX.
	(get_95_ifconf): Ditto.
	(get_ifconf): Handle SIOCGIFINDEX.  Fake it for loopback on systems
	not supporting IP Helper Lib.
	* include/asm/socket.h (SIOCGIFINDEX): Define.
	* include/cygwin/if.h (struct ifreq): Add member for interface index.
	(ifr_ifindex): Define.