v0.9.3.9 - AMD/OpenCL fixes

OpenCL UI inspect crash fixed, now UI more stable on AMD

GCN arch compatibility restored (RX 500, Vega), was broken last month

RDNA arch fixed (RX 6000,7000,9000)

still only 1/3 of normal FPS on RDNA (RX 6000,7000,9000)

so use smaller scenes starting 25K on newer AMD cards

also better nVidia performance in OpenCL mode