A stub opecl library that dynamically dlopen/dlsyms opencl implementations at runtime based on environment variables.
LIBOPENCL_SO_PATH -- Path to opencl so that will be searched first
LIBOPENCL_SO_PATH_2 -- Searched second
LIBOPENCL_SO_PATH_3 -- Searched third
LIBOPENCL_SO_PATH_4 -- Searched fourth
Default paths will be searched otherwise