What’s the deal with #if _LIBC and other non-Emacs code?

[Michal Nazarewicz]

Dear Emacs developers!

I’ve noticed quite some code in regex.c and regex.h which isn’t used by
Emacs or any executable distributed with Emacs.  Most notably, there are
blocks of code guarded with ‘#ifdef _LIBC’ macro and support for
alternative syntax which is never actually used.

To me this all looks like it could be safely removed simplifying and
shortening the code.

I would be happy to prepare patches doing just that, but first I’d like
to make sure that there’s nothing I’m missing.

-- 
Best regards
ミハウ “𝓶𝓲𝓷𝓪86” ナザレヴイツ
«If at first you don’t succeed, give up skydiving»