bug#44454: 26.3; Enhancement request: let :help in menus take a FORM arg, i.e., be eval'd

[Drew Adams <drew.adams@oracle.com>]

> > I have exactly this situation in my `Info' submenu
> > `Toggle/Cycle'.  For the toggle commands there, the
> > toggle checkmark suffices to let you know the current
> > (and hence the next) state/value.  For cycle commands
> > there's no way to know, except by actually cycling.
> 
> Makes sense to me.

BTW, another way to consider this is to look for
similarity with `help-echo'.  Not that the two
need to be similar, but that the use cases are
the same or similar for the value to be evaluated
rather than being restricted to a literal string.

(Yes, there's nothing special about the evaluation
for contexts where `help-echo' is used - it has
nothing, per se, to do with `help-echo', which is
just a property.  And yes, for menus, using a
FORM that gets evaluated (by the display engine,
IIUC) is a bit special.  But the use cases - the
usefulness for users, is of the same order.)