Version 3.20.9

Check that ExternalString objects get aligned resources.

Fixed JSArray-specific length lookup in polymorphic array handling (Chromium issues 263276, 263905).

Performance and stability improvements on all platforms.

git-svn-id: https://v8.googlecode.com/svn/trunk@15896 ce2b1a6d-e550-0410-aec6-3dcde31c8c00