bug#37820: 25.2; xref using etags incorrect case fold during completion

[Eli Zaretskii]

> Cc: shouman@comcast.net, 37820@debbugs.gnu.org
> From: Dmitry Gutov <dgutov@yandex.ru>
> Date: Fri, 17 Jan 2020 15:49:29 +0300
> 
> On 17.01.2020 11:28, Eli Zaretskii wrote:
> > Can you tell what is the difference in user-facing behavior due to
> > this change?  I'm not sure I understand that looking at the patch.
> 
> Identifier completion in xref-find-definitions (C-u M-. TAB TAB), when 
> the etags backend is in use, will honor the value of tags-case-fold-search.

Thanks.  This probably warrants to be mentioned in NEWS, but other
than that I'm okay with installing this on the release branch.