The state function depends on GL 2.0+ so it's unnecessary to
check for NV_POINT_SPRITE.

For some empty RECTs, such as { INT_MAX, INT_MAX, INT_MIN, INT_MIN }, right
minus left or bottom minus top underflow and wrap around to positive values.

wined3d: Use the same flags for wined3d_texture_set_color_key() and the "color_key_flags" field it sets.

This fixes a regression introduced by commit a8ab5694.

This is (mostly) equivalent to the vPos register in SM3.

Found by PVS-Studio.