i965: create code path to handle primitive restart in hardware

i965: create code path to handle primitive restart in hardware

For newer hardware we disable the VBO module's software handling
of primitive restart. We now handle primitive restarts in
brw_handle_primitive_restart.

The initial version of brw_handle_primitive_restart simply calls
vbo_sw_primitive_restart, and therefore still uses the VBO
module software primitive restart support.

Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>