[builtins] don't pre-flatten strings for JSStringIterator

[builtins] don't pre-flatten strings for JSStringIterator

Seems to be pretty perf-neutral (for the benchmarks we have in the tree) against
the pre-flattened version.

BUG=v8:5388
R=bmeurer@chromium.org, adamk@chromium.org, littledan@chromium.org

Committed: https://crrev.com/772ea9058827d11b7d947e04d98ea4cfb7b950d5
Cr-Commit-Position: refs/heads/master@{#39907}

[caitp, 2016-09-29 20:15:37]

The CQ bit was checked by caitp@igalia.com to run a CQ dry run

[commit-bot: I haz the power, 2016-09-29 20:15:44]

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

[caitp, 2016-09-29 20:17:06]

The CQ bit was checked by caitp@igalia.com to run a CQ dry run

[commit-bot: I haz the power, 2016-09-29 20:17:14]

Dry run: 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, 2016-09-29 20:46:10]

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

[commit-bot: I haz the power, 2016-09-29 20:46:11]

Dry run: This issue passed the CQ dry run.

[Benedikt Meurer, 2016-09-30 05:18:30]

Nice simplification. Thanks. LGTM.

[caitp, 2016-09-30 09:18:08]

The CQ bit was checked by caitp@igalia.com

[commit-bot: I haz the power, 2016-09-30 09:18:10]

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, 2016-09-30 09:20:05]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2016-09-30 09:20:19]

Description was changed from

==========
[builtins] don't pre-flatten strings for JSStringIterator

Seems to be pretty perf-neutral (for the benchmarks we have in the tree) against
the pre-flattened version.

BUG=v8:5388
R=bmeurer@chromium.org, adamk@chromium.org, littledan@chromium.org
==========

to

==========
[builtins] don't pre-flatten strings for JSStringIterator

Seems to be pretty perf-neutral (for the benchmarks we have in the tree) against
the pre-flattened version.

BUG=v8:5388
R=bmeurer@chromium.org, adamk@chromium.org, littledan@chromium.org

Committed: https://crrev.com/772ea9058827d11b7d947e04d98ea4cfb7b950d5
Cr-Commit-Position: refs/heads/master@{#39907}
==========

[commit-bot: I haz the power, 2016-09-30 09:20:20]

Patchset 3 (id:??) landed as
https://crrev.com/772ea9058827d11b7d947e04d98ea4cfb7b950d5
Cr-Commit-Position: refs/heads/master@{#39907}