X87: Test for var declarations in eval which conflict with let

X87: Test for var declarations in eval which conflict with let

port d515e5138d30ab5b2a79e4cac99fcc5ca8d8991b(r31211).

contributed by zhengxing.li@intel.com

original commit message:
Previously, name conflicts between var and let declarations were only made into exceptions if they were visible at parse-time. This patch adds runtime checks so that sloppy-mode direct eval can't introduce conflicting var declarations. The change is implemented by traversing the scope chain when a direct eval introduces a var declaration to look for conflicting let declarations, up to the function boundary.

additional comment:
The original r31211 patch needs some additional changes for x87
1. Should use Smi::FromInt(variable->DeclarationPropertyAttributes())

BUG=

Committed: https://crrev.com/a910b8f0e237152c521b1befae04c82b1e5065c5
Cr-Commit-Position: refs/heads/master@{#31433}

[shiyu.zhang, 2015-10-21 08:08:41]

Description was changed from

==========
x87

BUG=
==========

to

==========
X87: Test for var declarations in eval which conflict with let
    
port d515e5138d30ab5b2a79e4cac99fcc5ca8d8991b(r31211).
    
contributed by zhengxing.li@intel.com
    
original commit message:
Previously, name conflicts between var and let declarations were only made into
exceptions if they were visible at parse-time. This patch adds runtime checks so
that sloppy-mode direct eval can't introduce conflicting var declarations. The
change is implemented by traversing the scope chain when a direct eval
introduces a var declaration to look for conflicting let declarations, up to the
function boundary.
    
additional comment:
The original r31211 patch needs some additional changes for x87
1. Should use Smi::FromInt(variable->DeclarationPropertyAttributes())

BUG=
==========

[shiyu.zhang, 2015-10-21 08:11:08]

shiyu.zhang@intel.com changed reviewers:
+ chunyang.dai@intel.com, weiliang.lin@intel.com

[Weiliang, 2015-10-21 10:19:49]

The CQ bit was checked by weiliang.lin@intel.com

[Weiliang, 2015-10-21 10:19:49]

lgtm

[commit-bot: I haz the power, 2015-10-21 10:19:54]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1420683002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1420683002/1

[commit-bot: I haz the power, 2015-10-21 10:45:16]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-10-21 10:45:35]

Patchset 1 (id:??) landed as
https://crrev.com/a910b8f0e237152c521b1befae04c82b1e5065c5
Cr-Commit-Position: refs/heads/master@{#31433}