Comment # 38 on bug 110214 from Diego Viola

(In reply to Michel Dänzer from comment #37)
> Hmm, Mesa was built against LLVM 7 in Arch & Fedora, against LLVM 8/9 in
> Ubuntu. Maybe this was an LLVM issue fixed in version 8?

Unfortunately that's not the issue, llvm-libs 8.0.0 just landed on Arch Linux
[extra] repository and the issue still persists.