Reversed tmm-prompt items when tmm-mid-prompt is nil

[Thiago Melo]

Commit #5d844e1 fixed `tmm-prompt' for Emacs 29 (Bug#63754. Thanks,
Eli!) and even made the `tmm-mid-prompt' = nil option work again.

The fix also surfaced one inconsistency between nil and non-nil
`tmm-mid-prompt'.  When nil, the items shown by `tmm-prompt' are
reversed.

Compare these two cases:


(let ((tmm-mid-prompt "==>")
      (test-menu '("top" ("menu" ("foo" . 1) ("bar" . 2) ("baz" . 3)))))
  (tmm-prompt test-menu))

(let ((tmm-mid-prompt nil)
      (test-menu '("top" ("menu" ("foo" . 1) ("bar" . 2) ("baz" . 3)))))
  (tmm-prompt test-menu))


It seems innocuous and not worth a bug report.  Still, here's a way to
make this behavior more consistent:

--- a/lisp/tmm.el    2023-05-27 21:26:44.594743965 +0200
+++ b/lisp/tmm.el    2023-05-28 01:44:53.850880002 +0200
@@ -172,7 +172,7 @@ (defun tmm-prompt (menu &optional in-pop
        (let ((index-of-default 0))
          (if tmm-mid-prompt
          (setq tmm-km-list (tmm-add-shortcuts tmm-km-list))
-           t)
+           (setq tmm-km-list (reverse tmm-km-list)))
          ;; Find the default item's index within the menu bar.
          ;; We use this to decide the initial minibuffer contents
          ;; and initial history position.