I did finally get to this: I put together the pieces, and was able to build it, for the 16-bit platform mentioned on the webpage. It built with warnings... and then segfaulted. That's as far as I got so far, but I haven't forgotten!

(I just came across the Amsterdam Compiler Kit which is multi-architecture and has multiple language frontends and libraries. It has a small handful of contributors and is just about still active(*). I haven't looked to see whether it might make anything of a machine with 16-bit words.)

Cheers
Ed

(*) This was the Minix toolchain, it seems. The present 6.0 branch is a re-work, and it's no longer associated with Minix. It would seem that it works as a compiler to target the BBC Micro.