GL_NVX_gpu_memory_info
http://developer.download.nvidia.com/opengl/specs/GL_NVX_gpu_memory_info.txt
GL_NVX_gpu_memory_info
	GL_GPU_MEMORY_INFO_DEDICATED_VIDMEM_NVX 0x9047
	GL_GPU_MEMORY_INFO_TOTAL_AVAILABLE_MEMORY_NVX 0x9048
	GL_GPU_MEMORY_INFO_CURRENT_AVAILABLE_VIDMEM_NVX 0x9049
	GL_GPU_MEMORY_INFO_EVICTION_COUNT_NVX 0x904A
	GL_GPU_MEMORY_INFO_EVICTED_MEMORY_NVX 0x904B