Put RegExp js code in strict mode

Put RegExp js code in strict mode

src/js/regexp.js was one of the few files that was left in sloppy
mode. The ES2017 draft specification requires that writes to
lastIndex throw when the property is non-writable, and test262
tests enforce this behavior. This patch puts that file in strict
mode.

BUG=v8:4504
R=yangguo@chromium.org
LOG=Y

Committed: https://crrev.com/80b1b2a45bbd9bf3d08e4e6516acfaaa8f438213
Cr-Commit-Position: refs/heads/master@{#34801}

[Dan Ehrenberg, 2016-03-09 23:45:27]

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

[commit-bot: I haz the power, 2016-03-09 23:45:31]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1776883005/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1776883005/1

[commit-bot: I haz the power, 2016-03-09 23:56:21]

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

[commit-bot: I haz the power, 2016-03-09 23:56:22]

Dry run: Try jobs failed on following builders:
  v8_linux64_avx2_rel on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux64_avx2_rel/builds/...)

[Dan Ehrenberg, 2016-03-10 01:09:13]

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

[commit-bot: I haz the power, 2016-03-10 01:09:22]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1776883005/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1776883005/20001

[commit-bot: I haz the power, 2016-03-10 01:37:53]

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

[commit-bot: I haz the power, 2016-03-10 01:37:54]

Dry run: This issue passed the CQ dry run.

[Dan Ehrenberg, 2016-03-11 07:28:28]

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

[commit-bot: I haz the power, 2016-03-11 07:28:33]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1776883005/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1776883005/20001

[commit-bot: I haz the power, 2016-03-11 07:32:58]

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

[commit-bot: I haz the power, 2016-03-11 07:32:59]

Dry run: Try jobs failed on following builders:
  v8_linux_arm64_rel on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux_arm64_rel/builds/1...)

[Dan Ehrenberg, 2016-03-14 17:32:23]

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

[commit-bot: I haz the power, 2016-03-14 17:32:25]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1776883005/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1776883005/20001

[commit-bot: I haz the power, 2016-03-14 17:51:46]

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

[commit-bot: I haz the power, 2016-03-14 17:51:46]

Dry run: This issue passed the CQ dry run.

[Yang, 2016-03-15 06:56:36]

LGTM. Might be a good idea to run LayoutTests upfront though.

https://codereview.chromium.org/1776883005/diff/20001/test/mjsunit/regexp-las...
File test/mjsunit/regexp-lastIndex.js (right):

https://codereview.chromium.org/1776883005/diff/20001/test/mjsunit/regexp-las...
test/mjsunit/regexp-lastIndex.js:7: // set unconditionally. If a set fails, then
it acts as if in strict mode
I wonder whether it makes sense to discuss these funny rules in TC39 and fix
them. This is really surprising to me.

[Dan Ehrenberg, 2016-03-15 21:58:58]

On 2016/03/15 at 06:56:36, yangguo wrote:
> LGTM. Might be a good idea to run LayoutTests upfront though.
> 
>
https://codereview.chromium.org/1776883005/diff/20001/test/mjsunit/regexp-las...
> File test/mjsunit/regexp-lastIndex.js (right):
> 
>
https://codereview.chromium.org/1776883005/diff/20001/test/mjsunit/regexp-las...
> test/mjsunit/regexp-lastIndex.js:7: // set unconditionally. If a set fails,
then it acts as if in strict mode
> I wonder whether it makes sense to discuss these funny rules in TC39 and fix
them. This is really surprising to me.

I ran the LayoutTests and removed an invalid test as a result.

Re: discussing the rules at TC39: Good idea. Submitted an issue:
https://github.com/tc39/ecma262/issues/477

[Dan Ehrenberg, 2016-03-15 21:59:00]

The CQ bit was checked by littledan@chromium.org

[commit-bot: I haz the power, 2016-03-15 21:59:08]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1776883005/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1776883005/20001

[commit-bot: I haz the power, 2016-03-15 22:25:13]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-03-15 22:27:20]

Description was changed from

==========
Put RegExp js code in strict mode

src/js/regexp.js was one of the few files that was left in sloppy
mode. The ES2017 draft specification requires that writes to
lastIndex throw when the property is non-writable, and test262
tests enforce this behavior. This patch puts that file in strict
mode.

BUG=v8:4504
R=yangguo@chromium.org
LOG=Y
==========

to

==========
Put RegExp js code in strict mode

src/js/regexp.js was one of the few files that was left in sloppy
mode. The ES2017 draft specification requires that writes to
lastIndex throw when the property is non-writable, and test262
tests enforce this behavior. This patch puts that file in strict
mode.

BUG=v8:4504
R=yangguo@chromium.org
LOG=Y

Committed: https://crrev.com/80b1b2a45bbd9bf3d08e4e6516acfaaa8f438213
Cr-Commit-Position: refs/heads/master@{#34801}
==========

[commit-bot: I haz the power, 2016-03-15 22:27:21]

Patchset 2 (id:??) landed as
https://crrev.com/80b1b2a45bbd9bf3d08e4e6516acfaaa8f438213
Cr-Commit-Position: refs/heads/master@{#34801}

[Dan Ehrenberg, 2016-06-29 21:40:30]

A revert of this CL (patchset #2 id:20001) has been created in
https://codereview.chromium.org/2106803004/ by littledan@chromium.org.

The reason for reverting is: Found to break SAP Web IDE, and these semantics are
not shipped in any other browser.
Revert to legacy semantics while assessing web compatibility.

BUG=chromium:624318.