Upstream has slowed down a bit so it might make sense to have a stable version now. Not CCing Team AMD64 because I can take care of this one myself, just filing an issue for future reference.
Seeing as this will have to wait until dev-libs/ocl-icd has been stabilised, I'll CC Team AMD64 after all - just in case I happen not to be around when we are good to go.
amd64 stable. Closing.