st/mesa: Reduce array updates due to current changes.

st/mesa: Reduce array updates due to current changes.

Since using bitmasks we can easily check if we have any
current value that is potentially uploaded on array setup.
So check for any potential vertex program input that is not
already a vao enabled array. Only flag array update if there is
a potential overlap.

Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
Signed-off-by: Mathias Fröhlich <Mathias.Froehlich@web.de>