bug#64420: string-width of … is 2 in CJK environments

[Eli Zaretskii]

> From: SUNG TAE KIM <itaemu@gmail.com>
> Date: Mon, 17 Jul 2023 01:59:15 +0900
> Cc: 64420@debbugs.gnu.org
> 
> I see no issue in changing default width of ambiguous characters to
> narrow except variation selector blocks(FE00..FE0F, E0100..E01EF) and
> private-use blocks(E000..F8FF, F0000..FFFFD, 100000..10FFFD) because
> the characters in the former blocks are not standalone[1] and the
> characters of the latter blocks are reserved for 3rd-party and
> everything else seems standalone characters.
> 
> [1] https://en.wikipedia.org/wiki/Variation_Selectors_(Unicode_block)

Thanks.

I said I intend to end at #x324F because use-cjk-char-width-table
doesn't touch ambiguous characters with higher codepoints, so they are
already narrow in Emacs, and we don't need to "fix" them.