[turbofan] Fix typing rule for CheckBounds.

[turbofan] Fix typing rule for CheckBounds.

As of crrev.com/2760213003, the CheckBounds operator passes a truncation
that identfies zero and minus zero. However that was not reflected in
the typing rule, and as such the type of CheckBounds(-0,length) was
always Type::None. That confused the typed alias analysis in the
LoadElimination and led to ignoring StoreElement nodes.

BUG=chromium:708050
R=jarin@chromium.org

Review-Url: https://codereview.chromium.org/2812013006
Cr-Commit-Position: refs/heads/master@{#44598}
Committed: https://chromium.googlesource.com/v8/v8/+/483812d46cf96e26500b93b5b3d1cb9737236b2b

[Benedikt Meurer, 2017-04-12 08:36:25]

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

[commit-bot: I haz the power, 2017-04-12 08:36:34]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[Jarin, 2017-04-12 08:41:14]

lgtm

[Benedikt Meurer, 2017-04-12 08:42:04]

The CQ bit was unchecked by bmeurer@chromium.org

[Benedikt Meurer, 2017-04-12 08:42:07]

The CQ bit was checked by bmeurer@chromium.org

[commit-bot: I haz the power, 2017-04-12 08:42:16]

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, 2017-04-12 09:02:29]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1491986527415740, "parent_rev":
"8d2db536c9025f9bf18cc2f5422d752bff764135", "commit_rev":
"483812d46cf96e26500b93b5b3d1cb9737236b2b"}

[commit-bot: I haz the power, 2017-04-12 09:02:35]

Description was changed from

==========
[turbofan] Fix typing rule for CheckBounds.

As of crrev.com/2760213003, the CheckBounds operator passes a truncation
that identfies zero and minus zero. However that was not reflected in
the typing rule, and as such the type of CheckBounds(-0,length) was
always Type::None. That confused the typed alias analysis in the
LoadElimination and led to ignoring StoreElement nodes.

BUG=chromium:708050
R=jarin@chromium.org
==========

to

==========
[turbofan] Fix typing rule for CheckBounds.

As of crrev.com/2760213003, the CheckBounds operator passes a truncation
that identfies zero and minus zero. However that was not reflected in
the typing rule, and as such the type of CheckBounds(-0,length) was
always Type::None. That confused the typed alias analysis in the
LoadElimination and led to ignoring StoreElement nodes.

BUG=chromium:708050
R=jarin@chromium.org

Review-Url: https://codereview.chromium.org/2812013006
Cr-Commit-Position: refs/heads/master@{#44598}
Committed:
https://chromium.googlesource.com/v8/v8/+/483812d46cf96e26500b93b5b3d1cb97372...
==========

[commit-bot: I haz the power, 2017-04-12 09:02:36]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/v8/v8/+/483812d46cf96e26500b93b5b3d1cb97372...