bug#7742: 24.0.50; C-g does not dismiss popup menus

[Drew Adams]

emacs -Q
 
C-mouse-3 in some buffer, to bring up the popup menu.  C-g does not
dismiss the menu - you are trapped in the menu dialog/interaction.  You
must do something like click mouse-1 outside the menu to dismiss it.
 
Admittedly, it is usually easier in this context to click mouse-1 than
to hit C-g on the keyboard.  Still, C-g should DTRT.
 
(I'm guessing that this is hard to fix or it would have been fixed by
now.  But I don't know that, and it's good to record the bug anyway,
even if we don't intend to try to fix it anytime soon.)

In GNU Emacs 24.0.50.1 (i386-mingw-nt5.1.2600)
 of 2010-12-20 on 3249CTO
Windowing system distributor `Microsoft Corp.', version 5.1.2600
configured using `configure --with-gcc (4.4) --no-opt --cflags
-Ic:/imagesupport/include'