[turbofan] Fix unified stack slots for embedded constant pools.

[turbofan] Fix unified stack slots for embedded constant pools.

Account for the constant pool pointer slot during register allocation
data initialization.

R=danno@chromium.org, titzer@chromium.org, bmeurer@chromium.org, mcilroy@chromium.org,
TEST=cctest/test-run-machops/RunSpillConstantsAndParameters
BUG=

Committed: https://crrev.com/28f07b1c2b62d0757180efdee898016d61e434c1
Cr-Commit-Position: refs/heads/master@{#30430}

[MTBrandyberry, 2015-08-27 18:00:18]

mbrandy@us.ibm.com changed reviewers:
+ bmeurer@chromium.org, danno@chromium.org, mcilroy@chromium.org,
titzer@chromium.org

[MTBrandyberry, 2015-08-27 19:59:31]

On 2015/08/27 18:02:49, mtbrandyberry wrote:

This fix resolves the current set of buildbot test failures for PPC.

[Benedikt Meurer, 2015-08-28 05:49:13]

The CQ bit was checked by bmeurer@chromium.org

[Benedikt Meurer, 2015-08-28 05:49:13]

lgtm

[commit-bot: I haz the power, 2015-08-28 05:49:23]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1317123003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1317123003/1

[commit-bot: I haz the power, 2015-08-28 06:35:01]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-08-28 06:35:12]

Patchset 1 (id:??) landed as
https://crrev.com/28f07b1c2b62d0757180efdee898016d61e434c1
Cr-Commit-Position: refs/heads/master@{#30430}