bug#5726: Lost functionality in buffer item in menu bar from 22 to 23

[Chong Yidong]

> With Emacs 23, if I hit F10 and b I get this:
>
> --------------------
> screenshot----------------------------------------------------
> Possible completions are:
> n==>Next Buffer                        p==>Previous Buffer
> s==>Select Named Buffer...             l==>List All Buffers
> --------------------
> screenshot----------------------------------------------------

Thanks for the bug report.  This was fixed by Stefan's latest checkin to
the bzr repository (on the Emacs 23.2 branch).

2010-03-29  Stefan Monnier  <monnier@iro.umontreal.ca>

 Make tmm-menubar work for the Buffers menu again.
 * tmm.el (tmm-prompt): Also handle keymap entries in the form of
 vectors rather than cons cells, as used in menu-bar-update-buffers.