Various packages under minimal-bootstrap explicitly use the musl gcc
wrapper (especially the *-static packages).
In #494106, the desire is to allow these packages to run on a host
platform which may differ from the bootstrap seed platform. That host
platform may be a non-musl platform, and furthermore musl may not even
be available on the desired host architecture.
This change aims to make the packages more generic wrt libc. It is
extracted out of #494106.
Aleksi Hannula
745f12467c