Rename `org-babel-comint-prompt-regexp-old' to `...-fallback'

* lisp/ob-comint.el (org-babel-comint-prompt-regexp-fallback): Rename
to more accurate name.  Leave the old name as an alias.
(org-babel-comint--set-fallback-prompt): Use the new name.
(org-babel-comint-with-output):
(org-babel-comint-wait-for-output):
* lisp/ob-clojure.el (ob-clojure-eval-with-inf-clojure):
* lisp/ob-haskell.el (org-babel-interpret-haskell):
* lisp/ob-ruby.el (org-babel-ruby-initiate-session):
* lisp/ob-shell.el (org-babel-sh-initiate-session):

lisp/ob-clojure.el

@@ -237,8 +237,8 @@ or set the `:backend' header argument"))))
 			     "clojure" (format "clojure -A%s" alias)
 			     cmd0)
 		    cmd0)))
-	(setq
-         org-babel-comint-prompt-regexp-old comint-prompt-regexp
+	(setq-local
+         org-babel-comint-prompt-regexp-fallback comint-prompt-regexp
          comint-prompt-regexp inf-clojure-comint-prompt-regexp)
 	(funcall-interactively #'inf-clojure cmd)
 	(goto-char (point-max))))

lisp/ob-comint.el

@@ -58,7 +58,8 @@ executed inside the protection of `save-excursion' and
 	   (let ((comint-input-filter (lambda (_input) nil)))
 	     ,@body))))))
 
-(defvar-local org-babel-comint-prompt-regexp-old nil
+(defvaralias 'org-babel-comint-prompt-regexp-old 'org-babel-comint-prompt-regexp-fallback)
+(defvar org-babel-comint-prompt-regexp-fallback nil
   "Fallback regexp used to detect prompt.")
 
 (defcustom org-babel-comint-fallback-regexp-threshold 5.0
@@ -69,11 +70,11 @@ This is useful when prompt unexpectedly changes."
   :package-version '(Org . "9.7"))
 
 (defun org-babel-comint--set-fallback-prompt ()
-  "Swap `comint-prompt-regexp' and `org-babel-comint-prompt-regexp-old'."
-  (when org-babel-comint-prompt-regexp-old
+  "Swap `comint-prompt-regexp' and `org-babel-comint-prompt-regexp-fallback'."
+  (when org-babel-comint-prompt-regexp-fallback
     (let ((tmp comint-prompt-regexp))
-      (setq comint-prompt-regexp org-babel-comint-prompt-regexp-old
-            org-babel-comint-prompt-regexp-old tmp))))
+      (setq comint-prompt-regexp org-babel-comint-prompt-regexp-fallback
+            org-babel-comint-prompt-regexp-fallback tmp))))
 
 (defun org-babel-comint--prompt-filter (string &optional prompt-regexp)
   "Remove PROMPT-REGEXP from STRING.
@@ -144,7 +145,7 @@ or user `keyboard-quit' during execution of body."
 	     (accept-process-output
               (get-buffer-process (current-buffer))
               org-babel-comint-fallback-regexp-threshold)
-             (when (and org-babel-comint-prompt-regexp-old
+             (when (and org-babel-comint-prompt-regexp-fallback
                         (> (float-time (time-since start-time))
                            org-babel-comint-fallback-regexp-threshold)
                         (progn
@@ -154,7 +155,7 @@ or user `keyboard-quit' during execution of body."
                              (re-search-forward
 			      (regexp-quote ,eoe-indicator) nil t)
 			     (re-search-forward
-                              org-babel-comint-prompt-regexp-old nil t)))))
+                              org-babel-comint-prompt-regexp-fallback nil t)))))
                (org-babel-comint--set-fallback-prompt))))
 	 ;; replace cut dangling text
 	 (goto-char (process-mark (get-buffer-process (current-buffer))))
@@ -189,14 +190,14 @@ statement (not large blocks of code)."
         (accept-process-output
          (get-buffer-process buffer)
          org-babel-comint-fallback-regexp-threshold)
-        (when (and org-babel-comint-prompt-regexp-old
+        (when (and org-babel-comint-prompt-regexp-fallback
                    (> (float-time (time-since start-time))
                       org-babel-comint-fallback-regexp-threshold)
                    (progn
 		     (goto-char comint-last-input-end)
 		     (save-excursion
 		       (re-search-forward
-                        org-babel-comint-prompt-regexp-old nil t))))
+                        org-babel-comint-prompt-regexp-fallback nil t))))
           (org-babel-comint--set-fallback-prompt))))))
 
 (defun org-babel-comint-eval-invisibly-and-wait-for-file

lisp/ob-haskell.el

@@ -153,7 +153,7 @@ This function should only be called by `org-babel-execute:haskell'."
   (add-hook 'inferior-haskell-hook
             (lambda ()
               (setq-local
-               org-babel-comint-prompt-regexp-old comint-prompt-regexp
+               org-babel-comint-prompt-regexp-fallback comint-prompt-regexp
                comint-prompt-regexp
                (concat haskell-prompt-regexp "\\|^λ?> "))))
   (org-babel-haskell-with-session session params

lisp/ob-ruby.el

@@ -192,7 +192,7 @@ Session settings (`:ruby' header arg value) are taken from PARAMS."
             (when new-session?
               (with-current-buffer session-buffer
                 (setq-local
-                 org-babel-comint-prompt-regexp-old comint-prompt-regexp
+                 org-babel-comint-prompt-regexp-fallback comint-prompt-regexp
                  comint-prompt-regexp (concat "^" org-babel-ruby-prompt))
                 (insert org-babel-ruby-define-prompt ";")
                 (insert "_org_prompt_mode=conf.prompt_mode;conf.prompt_mode=:CUSTOM;")

lisp/ob-shell.el

@@ -294,7 +294,7 @@ var of the same value."
                   (alist-get t org-babel-shell-set-prompt-commands))
               org-babel-sh-prompt))
             (setq-local
-             org-babel-comint-prompt-regexp-old comint-prompt-regexp
+             org-babel-comint-prompt-regexp-fallback comint-prompt-regexp
              comint-prompt-regexp
              (concat "^" (regexp-quote org-babel-sh-prompt)
                      " *"))