Revert "Remove the binding for xref-quit-and-goto-xref"

This reverts commit 522c34f0e8.

Making changes to which there was an explicit disagreement
and a long discussion is unacceptable.  (Bug#44611)

doc/emacs/maintaining.texi

@@ -2242,9 +2242,10 @@ display it in the other window (@code{xref-prev-group}).
 Display the reference on the current line in the other window
 (@code{xref-show-location-at-point}).
 
-@kindex C-u RET
-To bury the @file{*xref*} buffer before displaying the reference, call
-@code{xref-goto-xref} with a prefix argument: @kbd{C-u RET}.
+@item @key{TAB}
+@findex xref-quit-and-goto-xref
+Display the reference on the current line and bury the @file{*xref*}
+buffer (@code{xref-quit-and-goto-xref}).
 
 @item r @var{pattern} @key{RET} @var{replacement} @key{RET}
 Perform interactive query-replace on references that match

etc/NEWS

@@ -1644,19 +1644,11 @@ in 'project-list-file'.
 
 ** xref
 
-+++
+---
 *** Prefix arg of 'xref-goto-xref' quits the "*xref*" buffer.
 So typing 'C-u RET' in the "*xref*" buffer quits its window
 before navigating to the selected location.
 
-+++
-*** The TAB binding in *xref* buffers has been removed. Use 'C-u RET' instead.
-To restore the old binding, say something like:
-
-    (require 'xref)
-    (define-key xref--xref-buffer-mode-map
-                (kbd "TAB") #'xref-quit-and-goto-xref)
-
 *** New user options 'xref-search-program' and 'xref-search-program-alist'.
 So far 'grep' and 'ripgrep' are supported.  'ripgrep' seems to offer better
 performance in certain cases, in particular for case-insensitive

lisp/progmodes/xref.el

@@ -817,6 +817,7 @@ ITEMS is an xref item which "
     (define-key map (kbd "P") #'xref-prev-group)
     (define-key map (kbd "r") #'xref-query-replace-in-results)
     (define-key map (kbd "RET") #'xref-goto-xref)
+    (define-key map (kbd "TAB")  #'xref-quit-and-goto-xref)
     (define-key map (kbd "C-o") #'xref-show-location-at-point)
     ;; suggested by Johan Claesson "to further reduce finger movement":
     (define-key map (kbd ".") #'xref-next-line)