Automatically move cursor to end of shell-mode buffer on M-p / M-n

[Andrew Pennebaker]

As a shell user, I want shell-mode M-p / M-n to automatically move my
cursor to the shell prompt, so that shell-mode behaves more intuitively.

Currently, attempting to use M-p / M-n when the cursor is not at the
prompt, results in a warning message. I think we can make shell-mode behave
more intuitively.

I have a workaround for this in my .emacs:

;; Automatically move cursor to prompt on shell up/down
(add-hook 'shell-mode-hook
          (lambda ()
            (define-key comint-mode-map (kbd "M-p")
              (lambda (arg)
                (interactive "*p")
                (goto-char (point-max))
                (comint-previous-input arg)))
            (define-key comint-mode-map (kbd "M-n")
              (lambda (arg)
                (interactive "*p")
                (goto-char (point-max))
                (comint-next-input arg)))))

In the next version of Emacs, could we bake this behavior in, so that
shell-mode behaves more intuitively?