bug#33992: 27.0.50; xref-find-definitions wastes too much space

[Juri Linkov]

> I thought that I didn't need to see the list of the xref results and the
> xrefs' window shrank the view of the code I wanted to study.  So, I came
> up with the defun below.  It presents the xref results without showing
> the xref window.  I think this idea can be further developed.
> xref-show--xrefs-buffer could have an 'm' key binding that "minimizes"
> its window by switching to xref-show-xrefs-without-buffer (below) and
> that function can "maximize" back with the same 'm' key.  A customizable
> variable could define the initial behavior.

This looks like good ol' find-tag and tags-loop-continue bound to M-,
with an optional pop-up to the xref buffer by a dedicated key.