bug#50666: 28.0.50; Fix native compilation on Cygwin

[Eli Zaretskii]

> From: ASSI <Stromeko@nexgo.de>
> Cc: ASSI <Stromeko@nexgo.de>,  50666@debbugs.gnu.org
> Date: Sun, 19 Sep 2021 13:31:09 +0200
> 
> Eli Zaretskii writes:
> > So this basically means that native-compilation is unworkable for
> > 32-bit Cygwin, right?
> 
> Explicit rebasing should work on both architectures, the question is
> just how to best ensure it's done correctly.

Since Emacs 28 performs native-compilation automatically in the
background, and also automatically loads the *.eln files once
produced, I'm not sure what you mean by "should work" if we assume the
user will have to rebase manually.