bug#45898: 27.1; wedged in redisplay again

[Eli Zaretskii]

> Date: Tue, 7 Jun 2022 10:03:26 -0400
> From: Devon Sean McCullough <Emacs-hacker2018@jovi.net>
> 
> On 2022-06-07 10:00, Eli Zaretskii wrote:
> > so-long-mode is not a guarantee of getting a responsive Emacs.
> 
> It is if you bury the un-displayable buffer.

If we succeed in knowing which buffer that is, which isn't easy (and
it could be shown in more than one window, btw) and bury it, then
there's no need for so-long-mode, is there?