I was unofficially doing weekly builds a while back, but I do not have the builds. I might get back into using FreeBSD after a long while of Windows dev. If that's the case, I'll try to be an official unofficial (yes, an official unofficial) clang build maintainer.
I should hopefully do a few build some time in the near future as I want to try to work on some cloud computing stuff with BSD. (Between tomorrow and the weekend)
Ah, and what builds do you want? I normally just build HEAD on amd64, but I sternly suggest that you ONLY run HEAD if you are planning on doing kernel dev and debugging for FreeBSD.
I can do other builds based on request, but each build takes about 30 minutes (buildworld->buildkernel->release) so I can't do an infinite amount. If you're not familiar, release yields a full ISO of the system, and since I would use clang, everything under the system would be built with clang. Note: This can lead to issues... so if you need stability, or do not know how to make patches for each issue you come along, I suggest not using clang full time yet.