bug#74339: 30.0.92; CC Mode stomps C TS Mode

[Eli Zaretskii <eliz@gnu.org>]

> Date: Tue, 26 Nov 2024 01:40:22 +0200
> Cc: monnier@iro.umontreal.ca, 74339@debbugs.gnu.org
> From: Dmitry Gutov <dmitry@gutov.dev>
> 
> On 25/11/2024 14:11, Eli Zaretskii wrote:
> > It's not consistency, it's the need to let users go from one
> > preference to another multiple times during the same session, and in a
> > documented way.
> 
> Okay. If we're going to document this though, could we make an explicit 
> note that it's a temporary solution? I.e. it's likely to stop working in 
> the next Emacs release.

This is somewhat problematic, since we have no good place for such
"temporary" documentation.  What we did instead is that Emacs 30
suggests to use major-mode-remap-alist as the first, and in most
places the only, way of preferring the tree-sitter based modes.  Both
NEWS and the user manual mention only this method.

So the support for changing the preference by loading a file is
already not advertised except in the commentary to c-ts-mode.el etc.
It is basically kept for users who remember doing that in Emacs 29.

Is that good enough?