* fhandler.h (class dev_console): Add `metabit' indicating the

current meta key mode.
	* fhandler_console.cc (fhandler_console::read): Set the top bit of
	the character if metabit is true.
	* fhandler_console.cc (fhandler_console::ioctl): Implement
	KDGKBMETA and KDSKBMETA commands.
	* fhandler_tty.cc (process_ioctl): Support KDSKBMETA.
	(fhandler_tty_slave::ioctl): Send KDGKBMETA and KDSKBMETA to the
	master.
	* include/cygwin/kd.h: New file for the meta key mode.
	* include/sys/kd.h: New file.

winsup/cygwin/fhandler.h

@@ -821,6 +821,7 @@ class dev_console
   unsigned rarg;
   bool saw_question_mark;
   bool alternate_charset_active;
+  bool metabit;
 
   char my_title_buf [TITLESIZE + 1];