In RegExp, lastIndex is read with ToLength, not ToInteger

In RegExp, lastIndex is read with ToLength, not ToInteger

ES2015 made a change vs ES5, where the "lastIndex" property of a
RegExp (which can be modified by a user to start the next search at
a different location) is cast to an integer with ToLength rather
than ToInteger. The main difference is on negative numbers, and
this is tested by test262. This patch implements that change on
RegExps and enables the test262 test now that it passes.

R=adamk
LOG=Y
BUG=v8:4244
Committed: https://crrev.com/1f61ac50338cc2ef1a54735206351f9798687248
Cr-Commit-Position: refs/heads/master@{#29715}

[adamk, 2015-07-15 00:35:52]

It looks to me like the test262 only exercises one of these code paths, though
surprisingly it's the test() codepath (not exec(), despite the test262
directory). Can you also add a test for the exec() case?

[Dan Ehrenberg, 2015-07-15 02:48:09]

On 2015/07/15 00:35:52, adamk wrote:
> It looks to me like the test262 only exercises one of these code paths, though
> surprisingly it's the test() codepath (not exec(), despite the test262
> directory). Can you also add a test for the exec() case?

I have a pull request out at https://github.com/tc39/test262/pull/369 . The test
passes on V8 with this patch.

[adamk, 2015-07-15 15:07:20]

lgtm

[Dan Ehrenberg, 2015-07-16 00:30:47]

The CQ bit was checked by littledan@chromium.org

[commit-bot: I haz the power, 2015-07-16 00:31:03]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1241713004/1

[commit-bot: I haz the power, 2015-07-16 01:12:24]

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

[commit-bot: I haz the power, 2015-07-16 01:12:25]

Try jobs failed on following builders:
  v8_linux_rel on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux_rel/builds/7662)

[Dan Ehrenberg, 2015-07-16 18:45:31]

The CQ bit was checked by littledan@chromium.org

[Dan Ehrenberg, 2015-07-16 18:45:32]

The patchset sent to the CQ was uploaded after l-g-t-m from adamk@chromium.org
Link to the patchset: https://codereview.chromium.org/1241713004/#ps20001
(title: "Disable invalid Mozilla test")

[commit-bot: I haz the power, 2015-07-16 18:46:02]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1241713004/20001

[commit-bot: I haz the power, 2015-07-16 19:30:21]

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

[commit-bot: I haz the power, 2015-07-16 19:30:22]

Try jobs failed on following builders:
  v8_linux_rel on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux_rel/builds/7704)

[Dan Ehrenberg, 2015-07-16 20:18:27]

The CQ bit was checked by littledan@chromium.org

[Dan Ehrenberg, 2015-07-16 20:18:28]

The patchset sent to the CQ was uploaded after l-g-t-m from adamk@chromium.org
Link to the patchset: https://codereview.chromium.org/1241713004/#ps40001
(title: "mark outdated test262")

[commit-bot: I haz the power, 2015-07-16 20:18:45]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1241713004/40001

[commit-bot: I haz the power, 2015-07-16 21:04:58]

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

[commit-bot: I haz the power, 2015-07-16 21:04:59]

Try jobs failed on following builders:
  v8_linux_rel on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux_rel/builds/7709)

[Dan Ehrenberg, 2015-07-16 21:14:24]

The CQ bit was checked by littledan@chromium.org

[Dan Ehrenberg, 2015-07-16 21:14:24]

The patchset sent to the CQ was uploaded after l-g-t-m from adamk@chromium.org
Link to the patchset: https://codereview.chromium.org/1241713004/#ps60001
(title: "Fix name of obsolete test262 test")

[commit-bot: I haz the power, 2015-07-16 21:14:45]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1241713004/60001

[commit-bot: I haz the power, 2015-07-16 21:55:36]

Committed patchset #4 (id:60001)

[commit-bot: I haz the power, 2015-07-16 21:55:53]

Patchset 4 (id:??) landed as
https://crrev.com/1f61ac50338cc2ef1a54735206351f9798687248
Cr-Commit-Position: refs/heads/master@{#29715}