BACKPORT: i965/rbc: Allocate mcs directly

such as we do for compressed msaa. In case of non-compressed simgle
sampled buffers the allocation of mcs is deferred until there is
actually a clear operation that needs the mcs.
In case of render buffer compression the mcs buffer always needed
and there is no real reason to defer the allocation. By doing it
directly allows to drop quite a bit unnecessary complexity.

Patch leaves brw_predraw_set_aux_buffers() a no-op. Subsequent
patches will re-use it and it seemed cleaner to leave it instead
of removing and re-introducing.

Adopted changes to ChromeOS Mesa version.

BUG=chrome-os-partner:59866
TEST=No Deqp regressions,
     No graphics corruption seen in App login dialog/ banners.

Signed-off-by: Topi Pohjolainen <topi.pohjolainen@intel.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
(cherry picked from 39712b2a14745861d06ab608ba9a56f1c006addc)
Signed-off-by: Kalyan Kondapally <kalyan.kondapally@intel.com>
Signed-off-by: Kevin Strasser <kevin.strasser@intel.com>

Change-Id: I89a16b23a31d8158dafae3133c5d45fdac7f362c
Reviewed-on: https://chromium-review.googlesource.com/419659
Reviewed-by: Stéphane Marchesin <marcheu@chromium.org>
Tested-by: Stéphane Marchesin <marcheu@chromium.org>
Commit-Queue: Stéphane Marchesin <marcheu@chromium.org>
5 files changed