bug#63253: 29.0.90; with-delayed-message fails in combination with inhibit-message

[Eli Zaretskii]

> Cc: mail@daniel-mendler.de, 63253@debbugs.gnu.org
> Date: Mon, 08 May 2023 17:55:08 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> 
> > So `set-message-function` is "dangerous" because it runs ELisp code from
> > `message3` => `message3_nolog` => `set_message`.
> 
> So I guess we need to have run_timers bind some variable, and then in
> set_message, if that variable is non-nil, we should avoid calling
> functions from set-message-function?

Or maybe (or in addition) regex-emacs.c should save and restore its
state around calls to maybe_quit?  Is that possible?