[turbofan] Simplify reduction if IfTrue and IfFalse and fix bugs.

[turbofan] Simplify reduction if IfTrue and IfFalse and fix bugs.

R=mstarzinger@chromium.org
BUG=chromium:451958
LOG=Y

Committed: https://crrev.com/7c81161b97504caedc93b01fa984791e9fb302c3
Cr-Commit-Position: refs/heads/master@{#26276}

[Michael Starzinger, 2015-01-26 15:28:08]

LGTM.

[titzer, 2015-01-26 15:41:52]

The CQ bit was checked by titzer@chromium.org

[commit-bot: I haz the power, 2015-01-26 15:42:19]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/880533002/1

[commit-bot: I haz the power, 2015-01-26 15:44:30]

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

[commit-bot: I haz the power, 2015-01-26 15:44:30]

Try jobs failed on following builders:
  v8_presubmit on tryserver.v8
(http://build.chromium.org/p/tryserver.v8/builders/v8_presubmit/builds/195)

[titzer, 2015-01-26 15:49:59]

The CQ bit was checked by titzer@chromium.org

[commit-bot: I haz the power, 2015-01-26 15:50:39]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/880533002/1

[commit-bot: I haz the power, 2015-01-26 16:11:22]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-26 16:11:34]

Patchset 1 (id:??) landed as
https://crrev.com/7c81161b97504caedc93b01fa984791e9fb302c3
Cr-Commit-Position: refs/heads/master@{#26276}