bug#62734: Always fully rebuild autoloads in package-generate-autoloads

[Eli Zaretskii]

> From: Philip Kaludercic <philipk@posteo.net>
> Cc: leo.gaskin@le0.gs,  62734@debbugs.gnu.org
> Date: Sun, 30 Apr 2023 09:17:16 +0000
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> >> > What happens if a package has no autoloads?  The doc string says in
> >> > that case passing EXTRA-DATA will produce OUTPUT-FILE regardless.
> >> > Does your patch handle that?  (It's hard to tell, given all the
> >> > whitespace changes in the patch.)
> >> 
> >> It would, as the else-case of the if branch I am proposing to eliminate
> >> would still insert the EXTRA-DATA.
> >
> > And if EXTRA-DATA is nil, then will we generate an empty OUTPUT file?
> 
> No, we still generate the right file with the right information (in this
> case just a `register-definition-prefixes' invocation).

OK, thanks.  Then please make sure this change survives both a
bootstrap and a "normal" build (where a bunch of *.el files need their
autoloads updated), and if so, please install on the emacs-29 branch.