bug#45412: File ... is large (... MiB), really open? (y)es or (n)o or (l)iterally

[Juri Linkov]

> The idea to show the help text also for graphical prompts is a good
> idea, but as there's no command already in Emacs that supports it,
> AFAIK, it could be a separate feature request.  What do you think?

Thanks.  While testing your patches, I noticed a compilation warning:

  emacs-lisp/rmc.el:29:1: Warning: Variable `buf' left uninitialized

Also these let-bindings are duplicated:

  (prompt (format "File %s is large (%s), really %s?"
                  (file-name-nondirectory filename)
                  (funcall byte-count-to-string-function size) op-type))

Otherwise, it looks nice, except of Eli's comment about the need
to keep graphical dialogs.