bug#44294: No widen by xref-find-definitions

[Juri Linkov]

BTW, I noticed that when isearch fails it doesn't inform the user
that there are possibly more matches outside the narrowed region:

diff --git a/lisp/isearch.el b/lisp/isearch.el
index c3d5ff2d31..dae7618556 100644
--- a/lisp/isearch.el
+++ b/lisp/isearch.el
@@ -3276,6 +3276,8 @@ isearch-message-prefix
                    (multi-isearch-file-list "multi-file ")
                    (multi-isearch-buffer-list "multi-buffer ")
                    (t ""))
+                  (if (and (not isearch-success) (buffer-narrowed-p) 
widen-automatically)
+                      "narrowed-buffer " "")
                   (or isearch-message-prefix-add "")
                   (if nonincremental "search" "I-search")
                   (if isearch-forward "" " backward")