[crankshaft] Fix another deopt loop in slow mode for-in.

[crankshaft] Fix another deopt loop in slow mode for-in.

The for-in slow mode implementation in Crankshaft unconditionally
deoptimizes when %ForInFilter returns undefined instead of just
skipping the item. Even worse, there's nothing we can learn from
that deopt, so we will eventually optimize again and hit exactly
the same problem again once we get back to optimized code.

R=mvstanton@chromium.org
BUG=v8:3650
LOG=n

Committed: https://crrev.com/5a7bb33e3f5e513611250d2edb688c3397ed8149
Cr-Commit-Position: refs/heads/master@{#33609}

[mvstanton, 2016-01-29 09:47:04]

lgtm

[Benedikt Meurer, 2016-01-29 09:50:17]

The CQ bit was checked by bmeurer@chromium.org

[commit-bot: I haz the power, 2016-01-29 09:50:24]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1647093002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1647093002/20001

[commit-bot: I haz the power, 2016-01-29 10:59:36]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-01-29 11:00:18]

Description was changed from

==========
[crankshaft] Fix another deopt loop in slow mode for-in.

The for-in slow mode implementation in Crankshaft unconditionally
deoptimizes when %ForInFilter returns undefined instead of just
skipping the item. Even worse, there's nothing we can learn from
that deopt, so we will eventually optimize again and hit exactly
the same problem again once we get back to optimized code.

R=mvstanton@chromium.org
BUG=v8:3650
LOG=n
==========

to

==========
[crankshaft] Fix another deopt loop in slow mode for-in.

The for-in slow mode implementation in Crankshaft unconditionally
deoptimizes when %ForInFilter returns undefined instead of just
skipping the item. Even worse, there's nothing we can learn from
that deopt, so we will eventually optimize again and hit exactly
the same problem again once we get back to optimized code.

R=mvstanton@chromium.org
BUG=v8:3650
LOG=n

Committed: https://crrev.com/5a7bb33e3f5e513611250d2edb688c3397ed8149
Cr-Commit-Position: refs/heads/master@{#33609}
==========

[commit-bot: I haz the power, 2016-01-29 11:00:19]

Patchset 2 (id:??) landed as
https://crrev.com/5a7bb33e3f5e513611250d2edb688c3397ed8149
Cr-Commit-Position: refs/heads/master@{#33609}