[turbofan] Robustify the GraphTrimmer.

[turbofan] Robustify the GraphTrimmer.

The GraphTrimmer should not ever see a dead node, except for the roots
that are explicitly fed into it. To defend against this, turn the
condition into a DCHECK.

R=jarin@chromium.org

Committed: https://crrev.com/86d1b7e83dc0fef3cc468eb62234a2d45ccb088e
Cr-Commit-Position: refs/heads/master@{#34001}

[Benedikt Meurer, 2016-02-15 12:31:31]

Hey Jaro,

Another small refactoring.
Please take a look.

Thanks,
Benedikt

[Benedikt Meurer, 2016-02-15 12:31:36]

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

[commit-bot: I haz the power, 2016-02-15 12:31:44]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1698883003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1698883003/1

[commit-bot: I haz the power, 2016-02-15 12:52:56]

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

[commit-bot: I haz the power, 2016-02-15 12:52:57]

Dry run: This issue passed the CQ dry run.

[Jarin, 2016-02-15 15:16:49]

lgtm

[Benedikt Meurer, 2016-02-15 17:25:56]

The CQ bit was checked by bmeurer@chromium.org

[commit-bot: I haz the power, 2016-02-15 17:26:07]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1698883003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1698883003/1

[commit-bot: I haz the power, 2016-02-15 17:28:18]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-02-15 17:28:52]

Description was changed from

==========
[turbofan] Robustify the GraphTrimmer.

The GraphTrimmer should not ever see a dead node, except for the roots
that are explicitly fed into it. To defend against this, turn the
condition into a DCHECK.

R=jarin@chromium.org
==========

to

==========
[turbofan] Robustify the GraphTrimmer.

The GraphTrimmer should not ever see a dead node, except for the roots
that are explicitly fed into it. To defend against this, turn the
condition into a DCHECK.

R=jarin@chromium.org

Committed: https://crrev.com/86d1b7e83dc0fef3cc468eb62234a2d45ccb088e
Cr-Commit-Position: refs/heads/master@{#34001}
==========

[commit-bot: I haz the power, 2016-02-15 17:28:53]

Patchset 1 (id:??) landed as
https://crrev.com/86d1b7e83dc0fef3cc468eb62234a2d45ccb088e
Cr-Commit-Position: refs/heads/master@{#34001}