Reland of [es6] ship regexp sticky flag. (patchset #1 id:1 of https://codereview.chromium.org/1531043002/ )

Reason for revert:
This can be relanded since the web compatibility fix in https://codereview.chromium.org/1543723002 has been submitted.

Original issue's description:
> Revert of [es6] ship regexp sticky flag. (patchset #2 id:20001 of https://codereview.chromium.org/1509733010/ )
>
> Reason for revert:
> This causes compatibility issues, as documented in https://bugs.chromium.org/p/v8/issues/detail?id=4617#c9
>
> Original issue's description:
> > [es6] ship regexp sticky flag.
> >
> > R=littledan@chromium.org
> > BUG=v8:4342
> > LOG=Y
> >
> > Committed: https://crrev.com/86c2dd4042dc9ce293e004234eb094f2b51d9640
> > Cr-Commit-Position: refs/heads/master@{#32826}
>
> TBR=yangguo@chromium.org
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=v8:4342

TBR=yangguo@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4342

Review URL: https://codereview.chromium.org/1546563002

Cr-Commit-Position: refs/heads/master@{#33003}