AMDGPU LLVM Adding GFX 9/10/11 "Generic Targets" To Build Once & Run On Multiple GPUs

Code merged today to mainline LLVM is preparing for the notion of generic targets across the GFX9, GFX10, and GFX11 GPU families. With follow-on work these generic targets are aiming to allow compiling code once and then running across multiple GPUs in the given hardware family...