[es6] Correct parsing of regular expression literal flags.

[es6] Correct parsing of regular expression literal flags.

ES6 section 12.2.8.1 states that flags for regular expression literals
must be checked during parsing and invalid flags are early errors. This
change adapts the Scanner and (Pre)Parser to act according to the spec.

This is also a prerequisite to unify the handling of literal creation
(for Objects, Arrays, Regexps, and at some point Classes).

R=yangguo@chromium.org

Committed: https://crrev.com/2732a6ad447b76ee0b74753c3452e28127d574d8
Cr-Commit-Position: refs/heads/master@{#32273}

[Benedikt Meurer, 2015-11-25 13:07:43]

Hey Yang,

Here's the fixup for regexp literal flags.
Please take a look.

Thanks,
Benedikt

[Yang, 2015-11-25 13:35:09]

LGTM!

[Benedikt Meurer, 2015-11-25 13:42:24]

The CQ bit was checked by bmeurer@chromium.org

[commit-bot: I haz the power, 2015-11-25 13:42:34]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1472323002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1472323002/20001

[commit-bot: I haz the power, 2015-11-25 13:46:18]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-11-25 13:46:53]

Patchset 2 (id:??) landed as
https://crrev.com/2732a6ad447b76ee0b74753c3452e28127d574d8
Cr-Commit-Position: refs/heads/master@{#32273}

[Michael Achenbach, 2015-11-25 15:06:12]

Can this have led to this flaky timeout?
https://build.chromium.org/p/client.v8/builders/V8%20Linux64%20-%20debug%20-%...