This should make it easier to take a minimal QEMU configuration and
carry it across releases.
In particular NEMU probably wants to make --without-default-devices the
default and adjust their default-configs/{aarch64,x86_64}-softmmu.mak file.
Thanks Yang from Intel and everyone from Red Hat that worked on this.
It's nice to see this completed after, ehm, 5.5 years.
Paolo