vbo: Correctly handle attribute offsets in dlist draw.

vbo: Correctly handle attribute offsets in dlist draw.

When executing a display list draw, for the offset
list to be correct, the offset computation needs to
accumulate all attribute size values in order.
Specifically, if we are shuffling around the position
and generic0 attributes, we may violate the order or
if we do not walk the generic vbo attributes we may
skip some of the attributes.
Even if this is an unlikely usecase we can fix this use
case by precomputing the offsets on the full attribute list
and store the full offset list in the display list node.

v2: Formatting fix
v3: Rebase

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