GL_ARB_cl_event
http://www.opengl.org/registry/specs/gl/ARB/cl_event.txt
GL_ARB_cl_event
	GL_SYNC_CL_EVENT_ARB 0x8240
	GL_SYNC_CL_EVENT_COMPLETE_ARB 0x8241
	GLsync glCreateSyncFromCLeventARB (cl_context context, cl_event event, GLbitfield flags)
	typedef struct _cl_context *cl_context
	typedef struct _cl_event *cl_event