Removing `packages-fixes`

[Stefan Monnier <monnier@iro.umontreal.ca>]

Hi,

The GNU ELPA `package-fixes` says:

    ;; This package can be safely installed on Emacs >= 25, in which
    ;; case it does nothing.

and does it via:

    ;;; Emacs < 25
    (unless (fboundp 'package--list-loaded-files)

but `package--list-loaded-files` has been removed from recent
`package.el` so the above test makes the package not "do nothing" any
more on recent Emacsen.

Given that the package has never been released anyway, is it still of
use or should we just remove it like we did with W3?


        Stefan