[es6] Fix Object built-in subclassing.

[es6] Fix Object built-in subclassing.

BUG=v8:3886
LOG=Y

Committed: https://crrev.com/059478165c1ae11e8ef84c7eba77c19494a8e443
Cr-Commit-Position: refs/heads/master@{#31760}

[Igor Sheludko, 2015-10-29 16:39:46]

ishell@chromium.org changed reviewers:
+ verwaest@chromium.org

[Igor Sheludko, 2015-10-29 16:39:47]

PTAL

[Igor Sheludko, 2015-10-29 19:55:40]

Patchset #1 (id:1) has been deleted

[Igor Sheludko, 2015-10-29 22:47:49]

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

[commit-bot: I haz the power, 2015-10-29 22:48:04]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1422853004/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1422853004/40001

[commit-bot: I haz the power, 2015-10-29 22:49:15]

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

[commit-bot: I haz the power, 2015-10-29 22:49:16]

Dry run: Try jobs failed on following builders:
  v8_android_arm_compile_rel on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_android_arm_compile_rel/...)
  v8_linux64_asan_rel on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux64_asan_rel/builds/...)
  v8_linux_arm_rel on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux_arm_rel/builds/9597)
  v8_linux_dbg on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux_dbg/builds/10212)
  v8_linux_mipsel_compile_rel on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux_mipsel_compile_rel...)
  v8_mac_rel on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_mac_rel/builds/11309)

[Igor Sheludko, 2015-10-30 11:13:08]

ishell@chromium.org changed reviewers:
+ mstarzinger@chromium.org

[Igor Sheludko, 2015-10-30 11:13:08]

Michi, is the new form of ObjectConstructor() good from the compiler's
perspective?

[Michael Starzinger, 2015-10-30 11:50:58]

On 2015/10/30 11:13:08, Igor Sheludko wrote:
> Michi, is the new form of ObjectConstructor() good from the compiler's
> perspective?

Yes, from a compiler point of view this looks good. I like it!

Just a random side-node, the "new.target" is already stored in a local variable
in the prologue, so hoisting it out into a local variable manually is never
needed, just accessing directly (as you did in this CL) is best. For FullCodegen
and TurboFan the optimization level should roughly be the same as
%_IsConstructCall currently. For Crankshaft it might be different, because
"new.target" causes a bailout at compilation time.

[Michael Starzinger, 2015-10-30 11:52:26]

https://codereview.chromium.org/1422853004/diff/40001/src/js/v8natives.js
File src/js/v8natives.js (right):

https://codereview.chromium.org/1422853004/diff/40001/src/js/v8natives.js#new...
src/js/v8natives.js:1327: if (GlobalObject != new.target &&
!IS_UNDEFINED(new.target)) {
Benedikt raised the question: Does this deal with "undetectable" objects
correctly?

[Toon Verwaest, 2015-11-02 09:30:56]

lgtm.

I raised the same issue. The spec says "If value is null, undefined or not
supplied, return ObjectCreate(%ObjectPrototype%).". What interpretation do you
give to the 'is' in that sentence? Currently we obviously say ==. Firefox seems
to say ===. I think the change here is fine as Igor wrote it.

[Igor Sheludko, 2015-11-03 17:47:10]

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

[commit-bot: I haz the power, 2015-11-03 17:47:15]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1422853004/60001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1422853004/60001

[commit-bot: I haz the power, 2015-11-03 18:14:27]

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

[commit-bot: I haz the power, 2015-11-03 18:14:28]

Dry run: This issue passed the CQ dry run.

[Igor Sheludko, 2015-11-03 18:19:24]

The CQ bit was checked by ishell@chromium.org

[Igor Sheludko, 2015-11-03 18:19:24]

The patchset sent to the CQ was uploaded after l-g-t-m from
verwaest@chromium.org
Link to the patchset: https://codereview.chromium.org/1422853004/#ps60001
(title: "Test updated")

[commit-bot: I haz the power, 2015-11-03 18:19:28]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1422853004/60001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1422853004/60001

[commit-bot: I haz the power, 2015-11-03 18:20:35]

Committed patchset #3 (id:60001)

[commit-bot: I haz the power, 2015-11-03 18:20:54]

Patchset 3 (id:??) landed as
https://crrev.com/059478165c1ae11e8ef84c7eba77c19494a8e443
Cr-Commit-Position: refs/heads/master@{#31760}