Trying Out AMDGPU DRM-Next Ahead Of Linux 4.20~5.0

With the two main set of AMDGPU DRM driver updates merged (one and two) to DRM-Next ahead of the next Linux kernel cycle, I decided to run some benchmarks on this code using Vega and Polaris hardware for seeing how the performance compares to that of the Linux 4.18 stable and Linux 4.19 Git kernels.