PPC/s390: Remove CONST_LEGACY VariableMode

PPC/s390: Remove CONST_LEGACY VariableMode

Port 7516fe1eaa7910015d7732a1aa34e45e3e37586c

Original commit message:

    The only remaining use of this VariableMode is for the names of sloppy
    named function expressions. This patch instead uses CONST for such
    bindings (just as we do in strict mode) and instead marks those
    Variables specially. During code generation a new helper method,
    Variable::throw_on_const_assignment(), is called to decide whether
    to throw or silently ignore the assignment.

R=adamk@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com, mbrandy@us.ibm.com
BUG=

Committed: https://crrev.com/3b40d4f2e5508644143ceda92e3da35273e8933e
Cr-Commit-Position: refs/heads/master@{#39060}

[JaideepBajwa, 2016-08-31 23:26:37]

PTAL

[john.yan, 2016-09-01 00:25:19]

lgtm

[JaideepBajwa, 2016-09-01 02:44:08]

The CQ bit was checked by bjaideep@ca.ibm.com

[commit-bot: I haz the power, 2016-09-01 02:44:11]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-09-01 03:06:21]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-09-01 03:07:07]

Description was changed from

==========
PPC/s390: Remove CONST_LEGACY VariableMode

Port 7516fe1eaa7910015d7732a1aa34e45e3e37586c

Original commit message:

    The only remaining use of this VariableMode is for the names of sloppy
    named function expressions. This patch instead uses CONST for such
    bindings (just as we do in strict mode) and instead marks those
    Variables specially. During code generation a new helper method,
    Variable::throw_on_const_assignment(), is called to decide whether
    to throw or silently ignore the assignment.

R=adamk@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com,
michael_dawson@ca.ibm.com, mbrandy@us.ibm.com
BUG=
==========

to

==========
PPC/s390: Remove CONST_LEGACY VariableMode

Port 7516fe1eaa7910015d7732a1aa34e45e3e37586c

Original commit message:

    The only remaining use of this VariableMode is for the names of sloppy
    named function expressions. This patch instead uses CONST for such
    bindings (just as we do in strict mode) and instead marks those
    Variables specially. During code generation a new helper method,
    Variable::throw_on_const_assignment(), is called to decide whether
    to throw or silently ignore the assignment.

R=adamk@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com,
michael_dawson@ca.ibm.com, mbrandy@us.ibm.com
BUG=

Committed: https://crrev.com/3b40d4f2e5508644143ceda92e3da35273e8933e
Cr-Commit-Position: refs/heads/master@{#39060}
==========

[commit-bot: I haz the power, 2016-09-01 03:07:08]

Patchset 1 (id:??) landed as
https://crrev.com/3b40d4f2e5508644143ceda92e3da35273e8933e
Cr-Commit-Position: refs/heads/master@{#39060}