bug#57152: 29.0.50; Emacs executable isn't rebuilt when loaddefs.el is modified

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Cc: 57152@debbugs.gnu.org
> Date: Wed, 17 Aug 2022 12:34:13 +0200
> 
> We could make loaddefs.el depend on all .el files, but then we'd rebuild
> the Emacs executable every time we change an .el file, and we don't want
> to do that, either.

What about using move-if-change?  That's a standard technique of
avoiding large rebuilds because some dependency's rules cannot be
easily stated.