[Mesa-dev] i965: Enable fast detiling paths for !llc

[Chris Wilson]

Just a small series to put the new cache-line read back to good use for
ye olde Xorg on bxt (and older/newer with very similar effect).

From

      40000 trep @   0.7007 msec (  1430.0/sec): ShmPutImage 500x500 square
       4000 trep @   9.0367 msec (   111.0/sec): ShmGetImage 500x500 square

to

      60000 trep @   0.5084 msec (  1970.0/sec): ShmPutImage 500x500 square
      12000 trep @   2.4808 msec (   403.0/sec): ShmGetImage 500x500 square