System Information
Operating system: Kubuntu 18.04
Graphics card: Vega 56, RX 480 8gb

Blender Version
Broken:
2.8 cc5bdf029324, 23:34
Worked:
Use AMDGPU-pro drivers but they only recognize RX480 8gb, or disconnect RX480 to use Vega 56 (it's not a blender issue)

Short description of error
ROCm 2.2 OpenCL kernels don't compile and hang, in blender it says is compiling but it never ends.

PS: AMDGPUpro 18.50 drivers recognize Vega 56 and RX480 8gb as different OpenCL platforms, but instead ROCm 2.2 and Windows 10 drivers put these GPUs correctly in the same OpenCL platform. https://community.amd.com/thread/237937
PS2: ROCm 2.2 OpenCL kernels compile in Luxrender though