MIPS: Refine '[stubs] Simplify the non-function case of CallConstructStub.'

MIPS: Refine '[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).

BUG=

Committed: https://crrev.com/d1ca012157b5d1a1201d7c96e24bdfc86fb5ea41
Cr-Commit-Position: refs/heads/master@{#30699}

[balazs.kilvady, 2015-09-11 12:49:51]

balazs.kilvady@imgtec.com changed reviewers:
+ akos.palfi@imgtec.com, bmeurer@chromium.org, danno@chromium.org,
paul.lind@imgtec.com

[paul.l..., 2015-09-11 13:46:57]

lgtm

[balazs.kilvady, 2015-09-11 14:43:48]

The CQ bit was checked by balazs.kilvady@imgtec.com

[commit-bot: I haz the power, 2015-09-11 14:43:54]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1340553002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1340553002/1

[commit-bot: I haz the power, 2015-09-11 15:12:40]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-09-11 15:12:56]

Patchset 1 (id:??) landed as
https://crrev.com/d1ca012157b5d1a1201d7c96e24bdfc86fb5ea41
Cr-Commit-Position: refs/heads/master@{#30699}