[es6] Fix prototype chain walk for instanceof.

[es6] Fix prototype chain walk for instanceof.

When walking up the prototype chain during OrdinaryHasInstance, we first
check if the current prototype equals the expected one, and only
afterwards check the current prototype against null. That's obviously
wrong if we check something like Proxy, whose prototype is null.

R=yangguo@chromium.org
BUG=v8:5085
Committed: https://crrev.com/eb1c9e2723d1d371699c6251aa56fd52535927a6
Cr-Commit-Position: refs/heads/master@{#36840}

[Benedikt Meurer, 2016-06-09 05:55:52]

Hey Yang,

Quickfix for ({}) instanceof Proxy.
Please take a look.

Thanks,
Benedikt

[Yang, 2016-06-09 05:57:46]

lgtm.

[Benedikt Meurer, 2016-06-09 05:58:00]

The CQ bit was checked by bmeurer@chromium.org

[commit-bot: I haz the power, 2016-06-09 05:58:05]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/2041103007/1

[commit-bot: I haz the power, 2016-06-09 06:22:15]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-06-09 06:26:15]

Description was changed from

==========
[es6] Fix prototype chain walk for instanceof.

When walking up the prototype chain during OrdinaryHasInstance, we first
check if the current prototype equals the expected one, and only
afterwards check the current prototype against null. That's obviously
wrong if we check something like Proxy, whose prototype is null.

R=yangguo@chromium.org
BUG=v8:5085
==========

to

==========
[es6] Fix prototype chain walk for instanceof.

When walking up the prototype chain during OrdinaryHasInstance, we first
check if the current prototype equals the expected one, and only
afterwards check the current prototype against null. That's obviously
wrong if we check something like Proxy, whose prototype is null.

R=yangguo@chromium.org
BUG=v8:5085

Committed: https://crrev.com/eb1c9e2723d1d371699c6251aa56fd52535927a6
Cr-Commit-Position: refs/heads/master@{#36840}
==========

[commit-bot: I haz the power, 2016-06-09 06:26:16]

Patchset 1 (id:??) landed as
https://crrev.com/eb1c9e2723d1d371699c6251aa56fd52535927a6
Cr-Commit-Position: refs/heads/master@{#36840}