Use LLVM 9 in mesa extensions
Fixes #895 (closed).
Tested vulkaninfo, vkcube, glxinfo, glxgears on both GL.default and GL.mesa-aco.
Edited by Valentin David
Fixes #895 (closed).
Tested vulkaninfo, vkcube, glxinfo, glxgears on both GL.default and GL.mesa-aco.