Revert of [es6] stage sticky regexps and RegExp.prototype.flags.

Revert of [es6] stage sticky regexps and RegExp.prototype.flags. (patchset #3 id:40001 of https://codereview.chromium.org/1412133002/ )

Reason for revert:
[sheriff] breaks nosnap:
http://build.chromium.org/p/client.v8/builders/V8%20Linux%20-%20nosnap/builds/4816

Original issue's description:
> [es6] stage sticky regexps and RegExp.prototype.flags.
>
> R=littledan@chromium.org
> BUG=v8:4342
> LOG=Y
>
> Committed: https://crrev.com/722719fe31fe7fd5bb50be6256b3581bb28a8169
> Cr-Commit-Position: refs/heads/master@{#31390}

TBR=littledan@chromium.org,yangguo@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4342
Committed: https://crrev.com/182ea8ad3f21cf381112f562c5fb6fa80e605d98
Cr-Commit-Position: refs/heads/master@{#31398}

[Michael Achenbach, 2015-10-20 07:53:10]

Created Revert of [es6] stage sticky regexps and RegExp.prototype.flags.

[commit-bot: I haz the power, 2015-10-20 07:53:19]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1403283004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1403283004/1

[commit-bot: I haz the power, 2015-10-20 07:53:29]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-10-20 07:53:44]

Patchset 1 (id:??) landed as
https://crrev.com/182ea8ad3f21cf381112f562c5fb6fa80e605d98
Cr-Commit-Position: refs/heads/master@{#31398}