bug#34908: Push mark in xref-push-marker-stack

[Juri Linkov <juri@linkov.net>]

>> I don't want to advertise this fix because the primary way to get back
>> for xref should be ‘M-,’.
>
> Well, it must be in NEWS, since this is a change in behavior.
>
> As for the manuals, it might be okay not to mention that, although I
> admit I don't understand your reasoning: something that is not a
> primary use doesn't automatically mean it shouldn't be documented.
>
>> Setting the mark is only needed for users who expect that every
>> significant change in position should leave a trace in the global
>> mark ring.
>
> I believe most of our commands that move to a far away position do set
> the mark.

Yes, most of these commands set the mark, but none of them mention this fact
in the manual.  I looked at

  (info "(emacs) Moving Point")
  (info "(emacs) Moving by Defuns")
  etc.

there is nothing about setting the mark, because it's so obvious
that doesn't need a special reminder for every command.

So I don't know what to write in NEWS, something along the lines:
"like all commands that move to a far away position
 xref-find-definitions now sets the mark as well
 but please remember that the primary way to pop xref mark
 is still M-, (xref-pop-marker-stack)" ?