bug#58558: 29.0.50; re-search-forward is slow in some buffers

[Eli Zaretskii]

> From: Ihor Radchenko <yantar92@posteo.net>
> Cc: Eli Zaretskii <eliz@gnu.org>, larsi@gnus.org, 58558@debbugs.gnu.org
> Date: Tue, 11 Apr 2023 11:29:26 +0000
> 
> Well. I just tried, but my Emacs-C foo is not good enough.
> The attached patch fails to compile.

That's because you've put DEFVAR_INT outside of any function.  They
should be inside one of the syms_of_* functions instead.
regex-emacs.c doesn't have such a function, but search.c does.  So
just move those DEFVAR_INT lines to syms_of_search, and I think it
will work.