OpenCL platform compatibility

Here is the list of working OpenCL platforms:

• Oclgrind (only for debugging purposes)
• Nvidia OpenCL 1.2 and OpenCL 3.0
• Intel OpenCL 1.2 runtime for Intel Core and Intel Xeon Processors 18.1
• Intel experimental runtime with SYCL support (some random segfaults are still present in some releases)
• Intel OpenCL 2.0 GPU Driver Package (64-bit)^2
• POCL pthread (Portable Computing Language)^2
• POCL CUDA backend (Portable Computing Language)^2
• POCL Vulkan backend (Portable Computing Language)^2
• AMDGPU-PRO^2
• AMD OpenCL 2.0 driver^2
• Mesa (clover)^2

^2 Should be tested