bug#74382: `compile-first` Make rule is no longer using `load-prefer-newer`

[Eli Zaretskii <eliz@gnu.org>]

> From: Konstantin Kharlamov <Hi-Angel@yandex.ru>
> Cc: Eli Zaretskii <eliz@gnu.org>, acm@muc.de, 74382@debbugs.gnu.org
> Date: Mon, 18 Nov 2024 13:05:54 +0300
> 
> Btw, thank you, this bit of history indeed is interesting. During whole
> discussion I had a question on the back of my mind: how this
> "distribute pre-built elc in tarballs" idea initially came to be. I
> mean, it's kind of nice from POV of saving a bit of energy around the
> world on CI machines, but I don't see much beyond that. Building elc
> files is not *that* bad for elc distribution to be strictly necessary.

Once again, building all the *.elc files takes a long time, even on
modern systems.  I have a 32-core screamer, and it still takes a few
minutes to byte-compile everything.  On an older system, it used to
take me 15 minutes even in parallel (-j4) builds.

Computers got much faster, but people know that, so they have less
patience.  Thus, avoiding recompilation of the *.elc files (and Info,
and other derived files) is still important to make the build faster.
A release tarball builds in less than 1 min due to these measures.

> Now that you told this, I realize it's just a solution to a problem
> from 25 years old back, from times when that actually was a problem.

I don't understand this conclusion.  What problem existed 25 years ago
that is related to "make clean" or to load-prefer-newer, and doesn't
exist anymore?