bug#56108: 29.0.50; ASAN use-after-free in re_match_2_internal

[Eli Zaretskii]

> Cc: 56108@debbugs.gnu.org
> Date: Thu, 23 Jun 2022 09:57:53 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> 
> > Do you want to do that or should I? 
> 
> Feel free to do it, I generally prefer that people who see the problem
> and could at least potentially test the solution also make the change
> to fix it.

Actually, let's first bring Stefan on board of this discussion.

Stefan, do you happen to know why some of the callers of
compile_pattern don't call freeze_pattern to protect the new cache
entry?  Is it just an omission or do we miss something here?