bug#37530: 26.1; Tack characters translated incorrectly

[Eli Zaretskii]

> From: Axel Svensson <mail@axelsvensson.com>
> Date: Fri, 27 Sep 2019 16:10:20 +0200
> Cc: Eli Zaretskii <eliz@gnu.org>, 37530@debbugs.gnu.org
> 
> I found three more keysyms missing:
> #define XKB_KEY_Ukrainian_ghe_with_upturn     0x06ad  /* U+0491
> CYRILLIC SMALL LETTER GHE WITH UPTURN */
> #define XKB_KEY_Ukrainian_GHE_WITH_UPTURN     0x06bd  /* U+0490
> CYRILLIC CAPITAL LETTER GHE WITH UPTURN */
> #define XKB_KEY_permille                      0x0ad5  /* U+2030 PER
> MILLE SIGN */
> This is according to
> https://github.com/xkbcommon/libxkbcommon/blob/master/xkbcommon/xkbcommon-keysyms.h

Do we know, or can find out, since what version of X are these
mappings in effect?  I think we should consider whether the version
where this appeared is old enough for us to use this unconditionally.