WIP/intel: Disable hiz on individual miptree slices

TODO: Refactor common stuff
TODO: doc

Signed-off-by: Chad Versace <chad.versace@linux.intel.com>
WIP: HiZ ambiguate immediately after creation

See workaround docs.
WIP/i965/blorp: Align vertices for hiz ops
WIP/intel: Don't calculate hiz_offset separately from depth_offset

TODO: Explain why.
TODO: See the TODO's in the patch.
intel: Enable hiz on Haswell

This patch sets the flag. That's all.

Signed-off-by: Chad Versace <chad.versace@linux.intel.com>
TODO
HACK: For testing hangs
SAVE