Version 3.26.27 (based on bleeding_edge revision r21017)

Error stack getter should not overwrite itself with a data property (issue 3294).

Performance and stability improvements on all platforms.

git-svn-id: https://v8.googlecode.com/svn/trunk@21031 ce2b1a6d-e550-0410-aec6-3dcde31c8c00