Version 3.26.4 (based on bleeding_edge revision r20446)

Make stray 'return' an early error.

Show references from weak containers as weak in heap snapshots (Chromium issue 356590).

Make invalid LHSs that are calls late errors (Chromium issue 358346).

Performance and stability improvements on all platforms.

git-svn-id: https://v8.googlecode.com/svn/trunk@20455 ce2b1a6d-e550-0410-aec6-3dcde31c8c00