bug#4446: remove ###autoload from ediff-hook.el

[Dan Nicolaescu <dann@ics.uci.edu>]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

  > > I found that setting preloaded-file-list in bootstrap-emacs does not
  > > work anyway. At that stage files are being loaded uncompiled, so extra
  > > files (eg cl) end up being added to preloaded-file-list due to
  > > eval-when-compile.
  > 
  > > Anyway, here's an attempt at your suggestion. The final version
  > > probably should not print the "skipped" message.
  > 
  > That looks pretty good.  There's still a "minor" problem that
  > lisp/makefile.w32 also needs update.
  > 
  > BTW, now that I think about it: is it really necessary to skip those
  > files?  I mean, what is the impact of having such redundant autoloads in
  > loaddefs.el?

From memory as I can't verify at the moment: the download size of the
emacs source is increased by > 10K, and the binary is 10KB bigger.

All of that is due to the single autoload line in ediff-hook.el, so the
can be solved by just removing that single line, or by killing the
ediff-hook.el file and moving the emacs specific code in menu-bar.el
(where it logically belongs anyway).