Version 3.28.31 (based on bleeding_edge revision r22513)

Remove harmony-typeof.

Implement String.prototype.codePointAt and String.fromCodePoint (issue 2840).

Performance and stability improvements on all platforms.

git-svn-id: https://v8.googlecode.com/svn/trunk@22515 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Merge remote-tracking branch 'upstream/trunk' into trunk