GL_ARB_gpu_shader5
http://www.opengl.org/registry/specs/gl/ARB/gpu_shader5.txt
GL_ARB_gpu_shader5
	GL_GEOMETRY_SHADER_INVOCATIONS 0x887F
	GL_MAX_GEOMETRY_SHADER_INVOCATIONS 0x8E5A
	GL_MIN_FRAGMENT_INTERPOLATION_OFFSET 0x8E5B
	GL_MAX_FRAGMENT_INTERPOLATION_OFFSET 0x8E5C
	GL_FRAGMENT_INTERPOLATION_OFFSET_BITS 0x8E5D
	GL_MAX_VERTEX_STREAMS 0x8E71