[RFA] windows-nat.c: Handle CTRL_BREAK_EVENT in ctrl_c_handler

[Eli Zaretskii]

> From: "Pierre Muller" <muller@ics.u-strasbg.fr>
> Date: Mon, 21 Sep 2009 17:24:35 +0200
> 
>   This patch allows me to interrupt a debuggee
> running in another console (with 'set new-console on')
> by pressing Ctrl-Break, even, if Ctrl-C has been
> transformed by the debuggee as a normal char
> using SetConsoleMode API function.

If this patch is accepted, please submit also a short change to the
manual, for the Windows-specific section, documenting this behavior.

Thanks.