hi/2 all
padoka ppa (aka unstable) is now on llvm 9 and mesa 19.1.
padoka stable is now on 18.3.3 waiting for 19.0 to go gold (will be compiled with llvm 8.0 stable).
enjoy.
https://launchpad.net/~paulo-miguel-dias/+archive/ubuntu/mesa
https://launchpad.net/~paulo-miguel-dias/+archive/ubuntu/pkppa