[turbofan] Simplify representation inference for add/subtract.

[turbofan] Simplify representation inference for add/subtract.

We don't really care about signedness when truncating to Word32.

Committed: https://crrev.com/b881465d7c913a771dffa1a9731fb4e0193a6693
Cr-Commit-Position: refs/heads/master@{#31779}

[Jarin, 2015-11-04 10:38:55]

Description was changed from

==========
[turbofan] Simplify representation inference for add/subtract.
==========

to

==========
[turbofan] Simplify representation inference for add/subtract.

We don't really care about signedness when truncating to Word32.
==========

[Jarin, 2015-11-04 10:40:16]

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

[Jarin, 2015-11-04 10:40:17]

Could you take a look, please?

Tests passed on my machine, so it must be correct. (/me running for cover
now...)

[Benedikt Meurer, 2015-11-04 10:42:25]

lgtm

[Jarin, 2015-11-04 10:47:05]

The CQ bit was checked by jarin@chromium.org

[commit-bot: I haz the power, 2015-11-04 10:47:12]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1417023005/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1417023005/1

[commit-bot: I haz the power, 2015-11-04 10:53:38]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-11-04 10:54:04]

Patchset 1 (id:??) landed as
https://crrev.com/b881465d7c913a771dffa1a9731fb4e0193a6693
Cr-Commit-Position: refs/heads/master@{#31779}