Native bindings to the AMD_pinned_memory extension.

This extension defines an interface that allows improved control of the physical memory used by the graphics device.

It allows an existing page of system memory allocated by the application to be used as memory directly accessible to the graphics processor. One example application of this functionality would be to be able to avoid an explicit synchronous copy with sub-system of the application; for instance it is possible to directly draw from a system memory copy of a video image.