drm/vmwgfx: Validate guest-backed shader const commands
drm/vmwgfx: Validate guest-backed shader const commands

Signed-off-by: Thomas Hellstrom <a26490dfbee4be3d38287ad6448444504f58193c@vmware.com>
Reviewed-by: Brian Paul <3cb4e1df5ec4da2c7c4af7c52cec8cf340a55a10@vmware.com>
Reviewed-by: Zack Rusin <6ab0df0692bc027e828ec9e4e9fbe8fa1a7842a8@vmware.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs