Create a new HandleScope for each JSON-parsed object to avoid excessive growth

Review URL: https://chromiumcodereview.appspot.com/12880019

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@14069 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
MIPS: Change LookupForWrite to always do a full lookup and check the result.

Port r14061 (df49702a)

Original commit message:
If we find a property in the prototype-chain that we can overwrite, and
we have a transition, keep the holder in the lookup-result as the actual
holder. We will need it for the consistency-check in GenerateStoreField.

By directly checking the entire chain we avoid having to lazily bail out
to a copy of the miss stub while generating the Field Store IC.

Currently this CL disallows a normal non-receiver holder, given that
that would require a positive lookup + details verification to ensure
the property did not become read-only. This fixes the regressions in the
attached tests.

BUG=

Review URL: https://codereview.chromium.org/12924011

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@14070 ce2b1a6d-e550-0410-aec6-3dcde31c8c00