r200: Prevent flush in middle of rendering.

r200: Prevent flush in middle of rendering.

Patch adds prediction functionthat tries to predict emit size to the smallest
possible values that is quarenteed to be higher than worst case scenario in
rendering pipeline.

State emit size prediction code is in place but fix for emit sizes is included
in next patch.

Signed-off-by: Pauli Nieminen <suokkos@gmail.com>