[turbofan] Improve representation selection for type guard.

[turbofan] Improve representation selection for type guard.

This takes into account the type of the type guard when choosing
representation for a node. To make the representation changes
unambiguous, we pass the restricted type to the changer.

BUG=chromium:726554
Review-Url: https://codereview.chromium.org/2920193004
Cr-Commit-Position: refs/heads/master@{#45734}
Committed: https://chromium.googlesource.com/v8/v8/+/5005faed5cd4890dd2eb28384f09e68b10d07df2

[Jarin, 2017-06-06 13:54:13]

The CQ bit was checked by jarin@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-06-06 13:54:23]

Dry run: CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[Jarin, 2017-06-06 14:00:55]

jarin@chromium.org changed reviewers:
+ bmeurer@chromium.org

[Jarin, 2017-06-06 14:00:57]

Could you take a look, please?

[Benedikt Meurer, 2017-06-06 14:02:28]

lgtm

[commit-bot: I haz the power, 2017-06-06 14:21:20]

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

[commit-bot: I haz the power, 2017-06-06 14:21:21]

Dry run: This issue passed the CQ dry run.

[Jarin, 2017-06-06 14:44:18]

The CQ bit was checked by jarin@chromium.org

[commit-bot: I haz the power, 2017-06-06 14:44:24]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-06-06 14:45:27]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1496760258188300, "parent_rev":
"c8e6cdfdcee0319fec69926e074d047f668c6f8b", "commit_rev":
"5005faed5cd4890dd2eb28384f09e68b10d07df2"}

[commit-bot: I haz the power, 2017-06-06 14:45:35]

Description was changed from

==========
[turbofan] Improve representation selection for type guard.

This takes into account the type of the type guard when choosing
representation for a node. To make the representation changes
unambiguous, we pass the restricted type to the changer.

BUG=chromium:726554
==========

to

==========
[turbofan] Improve representation selection for type guard.

This takes into account the type of the type guard when choosing
representation for a node. To make the representation changes
unambiguous, we pass the restricted type to the changer.

BUG=chromium:726554

Review-Url: https://codereview.chromium.org/2920193004
Cr-Commit-Position: refs/heads/master@{#45734}
Committed:
https://chromium.googlesource.com/v8/v8/+/5005faed5cd4890dd2eb28384f09e68b10d...
==========

[commit-bot: I haz the power, 2017-06-06 14:45:36]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/v8/v8/+/5005faed5cd4890dd2eb28384f09e68b10d...