bug#63028: 28.2; Rendering Traditional Mongolian Script

[Eli Zaretskii]

> Cc: 63028@debbugs.gnu.org
> Date: Sun, 23 Apr 2023 11:24:02 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> 
> In general, the Mongolian script has no composition rules defined for
> it in Emacs, which could be the main reason why this script is not
> displayed as you expect.  If you know of some reference for defining
> the character composition rules for Mongolian, please tell where those
> references could be found on the Internet.

Btw, it would be nice to have better support for Traditional Mongolian
in general; currently, we only have the script itself and the
characters which belong to it, and that's all.  Things to add:

  . input method(s)
  . HELLO text
  . font selection spec in fontset.el
  . character-composition rules

Patches welcome.