i965: Remove CACHED_BATCH support altogether.

i965: Remove CACHED_BATCH support altogether.

Using an unoptimized variant of glamor spending 50% of its CPU time in
brw_draw_prims() (and hitting the cache *very* frequently):

    N           Min           Max        Median           Avg        Stddev
x 200         29200         40500         34900         34750     958.43256
+ 200         31000         40300         34700         34622     916.35941
No difference proven at 95.0% confidence

Similarly, no difference on GLB2.7:

    N           Min           Max        Median           Avg        Stddev
x  63          64.1         71.36         70.69     70.113175     1.6782026
+  63          63.6         71.18         70.75     70.223651     1.6044186
No difference proven at 95.0% confidence

v2: Rebase on master (by anholt)
v3: Add a missing BEGIN_BATCH(3) to aa_line_parameters -- CACHED_BATCH
    didn't have the asserts about batchbuffer usage that ADVANCE_BATCH
    does, so we started assertion failing.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Anholt <eric@anholt.net>