st/nine: fix D3DRS_POINTSPRITE support, by testing the existence of the point sprite output register *after* parsing the vertex shader.

Signed-off-by: Xavier Bouchoux <xavierb@gmail.com>
Merge pull request #45 from xxxbxxx/for-upstream-3

st/nine: fix D3DRS_POINTSPRITE support, by testing the existence of the ...