i965: use cut index to handle primitive restart when possible

i965: use cut index to handle primitive restart when possible

If the primitive restart index and the primitive type can
be handled by the cut index feature, then use the hardware
to handle the primitive restart feature.

The VBO module's software handling of primitive restart is
used as a fall back.

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>