Port it to Alpha and let's see. I'll loan you my 21164 over the weekend.
It's fine for OpenBSD or NetBSD to support it, but Microsoft has not supported it in a long time.
I can't remember any other non-niche architecture with 8*2^n word size that shares this (mis-)feature. (I suspect that Cray 1 and it's derivates also share this, but that probably counts as niche architecture)