bug#56459: 29.0.50; Edebug disables Eldoc

[Eli Zaretskii]

> Cc: max.brieiev@gmail.com, larsi@gnus.org, 56459@debbugs.gnu.org,
>  friedman@splode.com
> Date: Wed, 01 Mar 2023 17:42:07 +0200
> From: Eli Zaretskii <eliz@gnu.org>
> 
> So I've now reverted that change, and I'm reopening the bug.  It will
> have to be fixed in some other way.

One possibility would be to show the ElDoc info on the mode line when
Edebug is active.  But the difficulty with that is to figure out how
to revert the mode line to the original shape when Edebug finishes.
We currently show the info on the mdoe line when the current buffer is
a minibuffer, and remove the info in minibuffer-exit-hook, but how to
do that in the Edebug case?