Add option for delete-pair to mark end of region

* lisp/emacs-lisp/lisp.el (delete-pair-push-mark): New user option.
(delete-pair): Use it.  (Bug#73284)

* etc/NEWS: Announce the new user option.

etc/NEWS

@@ -147,6 +147,12 @@ instead of raising an error.  Note that if you have disabled Transient
 Mark mode you might prefer to use 'unix-word-rubout', as this feature
 relies on there being an active region.
 
+---
+** New user option 'delete-pair-push-mark'.
+This option, if non-nil, makes 'delete-pair' push a mark at the end of
+the region enclosed by the deleted delimiters.  This makes it easy to
+act on that region.  For example, we can highlight it using 'C-x C-x'.
+
 
 * Changes in Specialized Modes and Packages in Emacs 31.1
 

lisp/emacs-lisp/lisp.el

@@ -850,10 +850,16 @@ It's used by the command `delete-pair'.  The value 0 disables blinking."
   :group 'lisp
   :version "28.1")
 
+(defcustom delete-pair-push-mark nil
+  "Non-nil means `delete-pair' pushes mark at end of delimited region."
+  :type 'boolean)
+
 (defun delete-pair (&optional arg)
   "Delete a pair of characters enclosing ARG sexps that follow point.
 A negative ARG deletes a pair around the preceding ARG sexps instead.
-The option `delete-pair-blink-delay' can disable blinking."
+The option `delete-pair-blink-delay' can disable blinking.  With
+`delete-pair-push-mark' enabled, pushes a mark at the end of the
+enclosed region."
   (interactive "P")
   (if arg
       (setq arg (prefix-numeric-value arg))
@@ -887,7 +893,9 @@ The option `delete-pair-blink-delay' can disable blinking."
 	  (when (and (numberp delete-pair-blink-delay)
 		     (> delete-pair-blink-delay 0))
 	    (sit-for delete-pair-blink-delay))
-	  (delete-char -1)))
+	  (delete-char -1)
+	  (when delete-pair-push-mark
+	    (push-mark))))
       (delete-char 1))))
 
 (defun raise-sexp (&optional n)