Upgrade cloudabi and cloudabi-utils to the latest upstream versions.

[ed]

Summary

This release of the CloudABI definitions contains some cleanups, such as
the removal of socket addresses. Though structures like sockaddr are
still defined by the C library, this information is no longer exposed by
runtimes. The reasoning being that additional services for CloudABI,
such as Flower, are going to facilitate this in the future:

https://github.com/NuxiNL/flower