[runtime] Add missing @@IsConcatSpreadable check for FAST_DOUBLE_ELEMENTS

[runtime] Add missing @@IsConcatSpreadable check for FAST_DOUBLE_ELEMENTS

A missing @@IsConcatSpreadable check caused the fast path inside the slow path
to be incorrect and follow the default concat strategy when the arguments
arrays contain only doubles.

BUG=chromium:668414
Committed: https://crrev.com/a09e5eda26d9cfe4c71d42b34bc1944c527e60bf
Cr-Commit-Position: refs/heads/master@{#41301}

[Camillo Bruni, 2016-11-24 13:13:00]

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

[commit-bot: I haz the power, 2016-11-24 13:13:08]

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

[Camillo Bruni, 2016-11-24 13:14:52]

cbruni@chromium.org changed reviewers:
+ ishell@chromium.org

[Camillo Bruni, 2016-11-24 13:14:53]

PTAL

[commit-bot: I haz the power, 2016-11-24 13:38:10]

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

[commit-bot: I haz the power, 2016-11-24 13:38:11]

Dry run: This issue passed the CQ dry run.

[Igor Sheludko, 2016-11-25 17:08:42]

lgtm

[Camillo Bruni, 2016-11-28 09:39:29]

The CQ bit was checked by cbruni@chromium.org

[commit-bot: I haz the power, 2016-11-28 09:39:37]

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, 2016-11-28 10:06:08]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1480325969971830, "parent_rev":
"f5a4b81cb4a5bf79e4498e8f8963a2dfb0c02ac4", "commit_rev":
"fee69375d469e75bb03b126bd3071de9546ef140"}

[commit-bot: I haz the power, 2016-11-28 10:06:13]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-11-28 10:06:21]

Description was changed from

==========
[runtime] Add missing @@IsConcatSpreadable check for FAST_DOUBLE_ELEMENTS

A missing @@IsConcatSpreadable check caused the fast path inside the slow path
to be incorrect and follow the default concat strategy when the arguments
arrays contain only doubles.

BUG=chromium:668414
==========

to

==========
[runtime] Add missing @@IsConcatSpreadable check for FAST_DOUBLE_ELEMENTS

A missing @@IsConcatSpreadable check caused the fast path inside the slow path
to be incorrect and follow the default concat strategy when the arguments
arrays contain only doubles.

BUG=chromium:668414

Committed: https://crrev.com/a09e5eda26d9cfe4c71d42b34bc1944c527e60bf
Cr-Commit-Position: refs/heads/master@{#41301}
==========

[commit-bot: I haz the power, 2016-11-28 10:06:22]

Patchset 1 (id:??) landed as
https://crrev.com/a09e5eda26d9cfe4c71d42b34bc1944c527e60bf
Cr-Commit-Position: refs/heads/master@{#41301}