PPC: Support immediate indices for StoreWriteBarrier.

PPC: Support immediate indices for StoreWriteBarrier.

Port 4eff883bcecaf24dfdcc6441e4558a9f5e69bd55
     c72b49bddcf1484bf3553ea702cf1764690a33df

Original commit message:
    Ideally we would not need the StoreWriteBarrier instructions at all,
    but represent the RecordWrite functionality as machine subgraph, but
    that'll take some time to get there. In the mean time we can have a
    shorter instruction sequence by recognizing immediate indices here.

R=bmeurer@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=

Committed: https://crrev.com/5ca122a12004c74979e85686c8b2d713890753ce
Cr-Commit-Position: refs/heads/master@{#34006}

[MTBrandyberry, 2016-02-15 18:09:17]

The CQ bit was checked by mbrandy@us.ibm.com to run a CQ dry run

[commit-bot: I haz the power, 2016-02-15 18:09:29]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1695333002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1695333002/1

[commit-bot: I haz the power, 2016-02-15 18:39:28]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-02-15 18:39:28]

Dry run: This issue passed the CQ dry run.

[dstence, 2016-02-15 18:54:18]

dstence@us.ibm.com changed reviewers:
+ dstence@us.ibm.com

[dstence, 2016-02-15 18:54:19]

lgtm

[MTBrandyberry, 2016-02-15 18:57:00]

The CQ bit was checked by mbrandy@us.ibm.com

[commit-bot: I haz the power, 2016-02-15 18:57:08]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1695333002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1695333002/1

[commit-bot: I haz the power, 2016-02-15 19:00:43]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-02-15 19:01:06]

Description was changed from

==========
PPC: Support immediate indices for StoreWriteBarrier.

Port 4eff883bcecaf24dfdcc6441e4558a9f5e69bd55
     c72b49bddcf1484bf3553ea702cf1764690a33df

Original commit message:
    Ideally we would not need the StoreWriteBarrier instructions at all,
    but represent the RecordWrite functionality as machine subgraph, but
    that'll take some time to get there. In the mean time we can have a
    shorter instruction sequence by recognizing immediate indices here.

R=bmeurer@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com,
michael_dawson@ca.ibm.com
BUG=
==========

to

==========
PPC: Support immediate indices for StoreWriteBarrier.

Port 4eff883bcecaf24dfdcc6441e4558a9f5e69bd55
     c72b49bddcf1484bf3553ea702cf1764690a33df

Original commit message:
    Ideally we would not need the StoreWriteBarrier instructions at all,
    but represent the RecordWrite functionality as machine subgraph, but
    that'll take some time to get there. In the mean time we can have a
    shorter instruction sequence by recognizing immediate indices here.

R=bmeurer@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com,
michael_dawson@ca.ibm.com
BUG=

Committed: https://crrev.com/5ca122a12004c74979e85686c8b2d713890753ce
Cr-Commit-Position: refs/heads/master@{#34006}
==========

[commit-bot: I haz the power, 2016-02-15 19:01:07]

Patchset 1 (id:??) landed as
https://crrev.com/5ca122a12004c74979e85686c8b2d713890753ce
Cr-Commit-Position: refs/heads/master@{#34006}