Add xref-file-name-display
* lisp/progmodes/xref.el (xref-file-name-display): New user variable. (xref-location-group): Use it. * etc/NEWS: Mention it.
* lisp/progmodes/xref.el (xref-file-name-display): New user variable. (xref-location-group): Use it. * etc/NEWS: Mention it.