Changes in lisp/Makefile.in to skip preloaded files

[Eli Zaretskii <eliz@gnu.org>]

> -autoloads: $(LOADDEFS) doit
> +# The Makefile dependency is to make any missing-file error more explicit.
> +autoloads: $(LOADDEFS) ../src/Makefile doit
>  	chmod +w $(lisp)/ps-print.el $(lisp)/emulation/tpu-edt.el \
>  	  $(lisp)/emacs-lisp/cl-loaddefs.el $(lisp)/mail/rmail.el \
>  	  $(lisp)/dired.el $(lisp)/ibuffer.el
>  	wd=$(lisp); $(setwins_almost); \
>  	echo Directories: $$wins; \
> -	$(emacs) -l autoload --eval '(setq generated-autoload-file "$(lisp)/loaddefs.el")' -f batch-update-autoloads $$wins
> +	preload=`sed -n -e '/^lisp=/ s/$${lispsource}//g p' ../src/Makefile | \
> +	  sed 's/^lisp= //'`; \
> +	$(emacs) -l autoload --eval "(setq generated-autoload-file \"$(lisp)/loaddefs.el\" autoload-excludes \"$${preload}\")" -f batch-update-autoloads $$wins

src/Makefile gets recreated every time you run the configure script,
so this change will now cause autoloads to appear out of date after
every configure.  Is that what you really want?  Should autoloads
depend on src/Makefile.in instead?

Similar with the preload= thing: why not run Sed on src/Makefile.in?
src/Makefile could be botched by some snafu; why both the lisp
directory on that behalf as well?