Trying Out The Radeon VII On Ubuntu 19.04 As Well As Linux 5.1 + Mesa 19.1

Following yesterday's Ubuntu 18.10 vs. 19.04 Radeon gaming/graphics benchmarks I decided to try out the Radeon VII on Ubuntu 19.04, which should be working out-of-the-box given its use of Linux 5.0 and Mesa 19.0. Unfortunately, earlier Radeon VII (Vega 20) issues I've been encountering are still plaguing the card...