> [...]
> Thank you for the review.  I will take a closer look at etc/CONTRIBUTE
> -- apparently I didn't read it in enough detail.  I will report back
> within the next few days.

New iteration.  As mentioned from my last message, I have reverted the
part where I tried to rewrite part of `archive-expunge' using `cl-do'.

Test cases for arc-mode still pass:
    $ make -C test arc-mode-tests

Note that I mentioned the new internal helper functions in the commit
message, as I saw João too has mentioned updates to internal functions
in 9d3fdf7e0.

If mentioning the internal functions turns out to be unnecessary, simply
removing these lines from the patch should suffice.  Otherwise, if
there's something else that looks wrong in the commit message, please
let me know.

FTR, I am still waiting for the counter signature from FSF before this
can be included into emacs.git.