Add kernel generator method to create kernel headers that combine 10s of small arrays as a single big array.

[tugrul512bit]

Some devices can not allocate arrays bigger than 128MB. With this feature, all free space (like 16GB) of VRAM can be used at once. It just requires power-of-2 sized sub-arrays and log(n) number of indexing-steps to select an element. As long as all workitems do similar indexing, it should work fast.

I don't know how else an OpenCL 1.2 kernel can access whole VRAM from a single buffer parameter.