[crankshaft] Refactor kAllowUndefinedAsNaN to kTruncatingToNumber.

[crankshaft] Refactor kAllowUndefinedAsNaN to kTruncatingToNumber.

The meaning of the HValue::kAllowUndefinedAsNaN is actually ToNumber
conversion (except for the uses in HBranch and HCompareHoleAndBranch,
which were confusing and useless anyways), so fix the naming to match
that.

Also properly integrate the handling of this flag with the existing
truncation analysis that is run as part of the representation changes
phase (i.e. where we already deal with truncating to int32 and smi).

This is done in preparation of allowing Crankshaft to handle any kind
of Oddball in the ToNumber truncation, instead of just undefined for
truncation ToNumber and undefined or boolean for ToInt32. It also helps
to make Crankshaft somewhat more compatible with the (saner)
implementation in TurboFan.

R=yangguo@chromium.org
BUG=v8:5400
Committed: https://crrev.com/df981a9ff5c875fcd0ed2056b371968d5887a595
Cr-Commit-Position: refs/heads/master@{#40577}

[Benedikt Meurer, 2016-10-26 07:29:38]

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

[commit-bot: I haz the power, 2016-10-26 07:29:46]

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

[Yang, 2016-10-26 07:39:22]

lgtm

[commit-bot: I haz the power, 2016-10-26 07:55:47]

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

[commit-bot: I haz the power, 2016-10-26 07:55:48]

Dry run: This issue passed the CQ dry run.

[Benedikt Meurer, 2016-10-26 08:02:22]

The CQ bit was checked by bmeurer@chromium.org

[commit-bot: I haz the power, 2016-10-26 08:02:32]

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, 2016-10-26 08:04:18]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-11-17 22:13:15]

Description was changed from

==========
[crankshaft] Refactor kAllowUndefinedAsNaN to kTruncatingToNumber.

The meaning of the HValue::kAllowUndefinedAsNaN is actually ToNumber
conversion (except for the uses in HBranch and HCompareHoleAndBranch,
which were confusing and useless anyways), so fix the naming to match
that.

Also properly integrate the handling of this flag with the existing
truncation analysis that is run as part of the representation changes
phase (i.e. where we already deal with truncating to int32 and smi).

This is done in preparation of allowing Crankshaft to handle any kind
of Oddball in the ToNumber truncation, instead of just undefined for
truncation ToNumber and undefined or boolean for ToInt32. It also helps
to make Crankshaft somewhat more compatible with the (saner)
implementation in TurboFan.

R=yangguo@chromium.org
BUG=v8:5400
==========

to

==========
[crankshaft] Refactor kAllowUndefinedAsNaN to kTruncatingToNumber.

The meaning of the HValue::kAllowUndefinedAsNaN is actually ToNumber
conversion (except for the uses in HBranch and HCompareHoleAndBranch,
which were confusing and useless anyways), so fix the naming to match
that.

Also properly integrate the handling of this flag with the existing
truncation analysis that is run as part of the representation changes
phase (i.e. where we already deal with truncating to int32 and smi).

This is done in preparation of allowing Crankshaft to handle any kind
of Oddball in the ToNumber truncation, instead of just undefined for
truncation ToNumber and undefined or boolean for ToInt32. It also helps
to make Crankshaft somewhat more compatible with the (saner)
implementation in TurboFan.

R=yangguo@chromium.org
BUG=v8:5400

Committed: https://crrev.com/df981a9ff5c875fcd0ed2056b371968d5887a595
Cr-Commit-Position: refs/heads/master@{#40577}
==========

[commit-bot: I haz the power, 2016-11-17 22:13:16]

Patchset 1 (id:??) landed as
https://crrev.com/df981a9ff5c875fcd0ed2056b371968d5887a595
Cr-Commit-Position: refs/heads/master@{#40577}