It's not a mesa change that caused this. I have the same problem with Hawaii. The first time I saw this I tried an older version of mesa which worked a day before and the problem was still there. I can't say which change in llvm caused this, because I'm only building mesa on my own and receive a prebuilt llvm copy from a repository. I can upload a backtrace as well if you want, but the segfault I see also happens in SlotIndex::getIndex().