i965: Use 8x4 aligned rectangles for HiZ operations on Broadwell.

i965: Use 8x4 aligned rectangles for HiZ operations on Broadwell.

Like on Haswell, we need to use 8x4 aligned rectangle primitives for
hierarchical depth buffer resolves and depth clears.  See the comments
in brw_blorp.cpp's brw_hiz_op_params() constructor.  (The Broadwell
documentation confirms that this is still necessary.)

This patch makes the Broadwell code follow the same behavior as Chad and
Jordan's Gen7 BLORP code.  Based on a patch by Topi Pohjolainen.

This fixes es3conform's framebuffer_blit_functionality_scissor_blit
test, with no Piglit regressions.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Cc: "10.2" <mesa-stable@lists.freedesktop.org>