[regexp] Only access result.groups if named captures are enabled

[regexp] Only access result.groups if named captures are enabled

GetProperty(result, groups) needs to be called iff the
harmony-regexp-named-captures flag is enabled.

Also add a couple of DCHECKS.

BUG=v8:5437, chromium:706748
Review-Url: https://codereview.chromium.org/2786933002
Cr-Commit-Position: refs/heads/master@{#44267}
Committed: https://chromium.googlesource.com/v8/v8/+/1200cc2c6d715466ee762a05ae26fe4a4f82eb36

[jgruber, 2017-03-30 09:44:19]

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

[commit-bot: I haz the power, 2017-03-30 09:44:30]

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

[jgruber, 2017-03-30 09:45:31]

jgruber@chromium.org changed reviewers:
+ yangguo@chromium.org

[commit-bot: I haz the power, 2017-03-30 10:12:25]

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

[commit-bot: I haz the power, 2017-03-30 10:12:26]

Dry run: This issue passed the CQ dry run.

[Yang, 2017-03-30 11:50:51]

lgtm

[jgruber, 2017-03-30 11:53:48]

The CQ bit was checked by jgruber@chromium.org

[commit-bot: I haz the power, 2017-03-30 11:53:59]

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, 2017-03-30 11:55:11]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1490874828921350, "parent_rev":
"b6912850dffa2e6ba52d2c254cc5b72761e63f6d", "commit_rev":
"1200cc2c6d715466ee762a05ae26fe4a4f82eb36"}

[commit-bot: I haz the power, 2017-03-30 11:55:16]

Description was changed from

==========
[regexp] Only access result.groups if named captures are enabled

GetProperty(result, groups) needs to be called iff the
harmony-regexp-named-captures flag is enabled.

Also add a couple of DCHECKS.

BUG=v8:5437,chromium:706748
==========

to

==========
[regexp] Only access result.groups if named captures are enabled

GetProperty(result, groups) needs to be called iff the
harmony-regexp-named-captures flag is enabled.

Also add a couple of DCHECKS.

BUG=v8:5437,chromium:706748

Review-Url: https://codereview.chromium.org/2786933002
Cr-Commit-Position: refs/heads/master@{#44267}
Committed:
https://chromium.googlesource.com/v8/v8/+/1200cc2c6d715466ee762a05ae26fe4a4f8...
==========

[commit-bot: I haz the power, 2017-03-30 11:55:17]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/v8/v8/+/1200cc2c6d715466ee762a05ae26fe4a4f8...