Based largely on a patch by Sebastian Lackner.
Adapted from "Improve ValidateVertexShader()" by Henri Verbeet.
Signed-off-by: Gijs Vermeulen <gijsvrm@gmail.com>
Signed-off-by: Henri Verbeet <hverbeet@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>