PPC: [stubs] Simplify the non-function case of CallConstructStub.

PPC: [stubs] Simplify the non-function case of CallConstructStub.

Port 622fa0ea21b3517b1feaed447c87e580bafac865

Original commit message:
    Currently we do this dance between the CallConstructStub, the
    CALL_* builtins and the %GetConstructorDelegate, %GetProxyTrap,
    and %Apply runtime functions for every [[Construct]] operation on
    non-function callables. This is complexity is unnecessary, and can
    be simplified to work without any JS builtin. This will also make it
    a lot easier to implement ES6 compliant [[Construct]] for proxies.

    Also sanitize the invariant for CallConstructStub, which up until now
    always restored the context itself, but that force us to always create
    another copy of all arguments in case of proxies and other callables,
    so we can relax that constraint by making the caller restore the context
    (this only affects fullcodegen, since the optimizing compilers already
    properly restore the context anyway).

R=bmeurer@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com, dstence@us.ibm.com
BUG=

Committed: https://crrev.com/e7a3e2aae4270c7f368ea4172d98f03512f5aeab
Cr-Commit-Position: refs/heads/master@{#30696}

[MTBrandyberry, 2015-09-11 14:23:26]

The CQ bit was checked by mbrandy@us.ibm.com to run a CQ dry run

[commit-bot: I haz the power, 2015-09-11 14:23:32]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1338663003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1338663003/1

[commit-bot: I haz the power, 2015-09-11 14:49:32]

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

[commit-bot: I haz the power, 2015-09-11 14:49:33]

Dry run: This issue passed the CQ dry run.

[john.yan, 2015-09-11 15:05:23]

lgtm

[MTBrandyberry, 2015-09-11 15:05:49]

The CQ bit was checked by mbrandy@us.ibm.com

[commit-bot: I haz the power, 2015-09-11 15:06:01]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1338663003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1338663003/1

[commit-bot: I haz the power, 2015-09-11 15:07:47]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-09-11 15:08:06]

Patchset 1 (id:??) landed as
https://crrev.com/e7a3e2aae4270c7f368ea4172d98f03512f5aeab
Cr-Commit-Position: refs/heads/master@{#30696}