Using RX VEGA is possible on Mesa3D OpenCL (GalliumCompute)
I tried to compile a missing component 'libclc' (OpenCL library) for RX VEGA. Fortunatelly, the trivial changes in configure script causes correct compilation and installation. I am using this version of libclc with Mesa3D 17.3.0-rc4 and LLVM 5.0.1rc1. 'clinfo' works correctly and prints all informations about devices (including RX VEGA). Simple programs also works correctly on RX VEGA with this version libclc. Currently I am testing that stuff with AMDGPU-PRO drivers (kernels and modules), however that stuff can be work correctly under other kernels or RadeonSI driver.
Finally, RX VEGA is usable under Mesa3D GalliumCompute (Clover) with latest version of the rest components.
This is alternative for users who do not have hardware that is compliant with ROCm platform (older Ivy Bridge processors, or not full PCI-Express slots or PCI-Express without atomics support) and who needs some (ugly) OpenCL support to use our software.