Comment # 7 on bug 108318 from John Galt

(In reply to Alex Deucher from comment #6)
> Seems more likely to be an LLVM or Mesa bug than a kernel one.

I went back to 4.18.7 and it persisted, so you're correct. It was okay early on
at 18.2.0 with llvm svn. I'll go back to 18.2.0 to test, and if it's broken
then we know it's llvm.