bug#72808: 30.0.90; editorconfig doesn't set tab_width to a default value

[Eli Zaretskii <eliz@gnu.org>]

> Cc: Damien Cassou <damien@cassou.me>, 72808@debbugs.gnu.org,
>  jaygkamat@gmail.com, 8.slashes@gmail.com
> Date: Thu, 31 Oct 2024 22:42:31 -0400
> From:  Stefan Monnier via "Bug reports for GNU Emacs,
>  the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
> 
> Note that in response to the very similar request in bug#73991 (where
> I also point out more reasons why I think the EditorConfig spec is just
> poorly thought out in this respect), I (reluctantly🙂) installed in
> `emacs-30` a patch which should make Emacs behave like Damien expects
> for the `.editorconfig` file he provided.

Indeed.  Moreover, people who claim that we must behave like other
editors should also explain how to reconcile that with the fact that
Emacs has a much more complex handling of tab-width wrt indentation,
and in particular we almost completely decoupled these two.  It is
IMNSHO unthinkable that support of EditorConfig will change how Emacs
handles tabs and indentation in its various major modes.

So saying that we should comply is not enough, because everyone here
is in favor of compliance.  The problem, and the reason why Stefan
didn't comply 100% with that single setting, is that there are
significant conceptual problems with providing such compliance without
breaking expectations of Emacs users.  Thus, if you think what we have
is insufficient, please tell how to be more compatible without
breaking traditional Emacs behaviors wrt to tabs and indentation.
Because we cannot possibly allow that tail to wag the dog, can we?