i965: Move pre-draw resolve buffers to dd::UpdateState

i965: Move pre-draw resolve buffers to dd::UpdateState

No functional change except for glBegin/glEnd style rendering, where we now
do the resolves at glBegin time instead of FLUSH_VERTICES time.  This is also
the reason for this change, so that when we later switch fast clear resolve to
use meta, we won't be doing meta operations in the middle of a begin/end
sequence.

Signed-off-by: Kristian Høgsberg <krh@bitplanet.net>
Acked-by: Kenneth Graunke <kenneth@whitecape.org>