bug#66117: 30.0.50; `find-buffer-visiting' is slow when opening large number of buffers

[Eli Zaretskii]

> From: Ihor Radchenko <yantar92@posteo.net>
> Cc: monnier@iro.umontreal.ca, dmitry@gutov.dev, 66117@debbugs.gnu.org,
>  mattias.engdegard@gmail.com
> Date: Thu, 14 Dec 2023 14:20:18 +0000
> 
> Then, I think that having a global variable like
> `case-fold-search-override' could make things more predictable if we
> advertise it for let-bindings.
> Also, it is much easier to implement.
> WDYT?

I'd choose a different name (since this is supposed to affect any
matching, not just search).

And then we will need to decide which case-equivalence table this will
use.  The current default is affected by language-environment, so it
might not be a good idea (it causes known problems in Turkish locales,
for example).  Perhaps we need a new standard kind of table for that.

But for starters, a new Lisp-only global variable should be good, I
think.  Stefan, any comments?