[turbofan] Use an IntPtrConstant in WordEqual comparisons.

[turbofan] Use an IntPtrConstant in WordEqual comparisons.

ZeroConstant is a NumberConstant, so does not get matched
in IntMatchers, which results in missing some opportunities
in instruction selection. Use IntPtrConstant instead, which
generates an Int32Constant or an Int64Constant depending on
the word size.

BUG=

Committed: https://crrev.com/70dfb5a0d648ade2936b3203b53cde5a9abf660a
Cr-Commit-Position: refs/heads/master@{#40669}

[georgia.kouveli, 2016-10-31 11:48:35]

georgia.kouveli@arm.com changed reviewers:
+ bmeurer@chromium.org, epertoso@chromium.org

[epertoso, 2016-10-31 11:54:33]

lgtm, thank you!

[georgia.kouveli, 2016-10-31 11:55:32]

The CQ bit was checked by georgia.kouveli@arm.com

[commit-bot: I haz the power, 2016-10-31 11:55:34]

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, 2016-10-31 12:23:11]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-11-17 22:17:57]

Description was changed from

==========
[turbofan] Use an IntPtrConstant in WordEqual comparisons.

ZeroConstant is a NumberConstant, so does not get matched
in IntMatchers, which results in missing some opportunities
in instruction selection. Use IntPtrConstant instead, which
generates an Int32Constant or an Int64Constant depending on
the word size.

BUG=
==========

to

==========
[turbofan] Use an IntPtrConstant in WordEqual comparisons.

ZeroConstant is a NumberConstant, so does not get matched
in IntMatchers, which results in missing some opportunities
in instruction selection. Use IntPtrConstant instead, which
generates an Int32Constant or an Int64Constant depending on
the word size.

BUG=

Committed: https://crrev.com/70dfb5a0d648ade2936b3203b53cde5a9abf660a
Cr-Commit-Position: refs/heads/master@{#40669}
==========

[commit-bot: I haz the power, 2016-11-17 22:17:58]

Patchset 1 (id:??) landed as
https://crrev.com/70dfb5a0d648ade2936b3203b53cde5a9abf660a
Cr-Commit-Position: refs/heads/master@{#40669}