Version 3.20.6

Try to remove invalidated stubs before falling back to checking the constant state (Chromium issue 260585).

Fixed gyp_v8 to work with use_system_icu=1 (issue 2475).

Fixed sloppy-mode 'const' under Harmony flag (Chromium issue 173361).

Use internal array as API function cache  (Chromium issue 260106).

Fixed possible stack overflow in range analysis (Chromium issue 259452).

Performance and stability improvements on all platforms.

git-svn-id: https://v8.googlecode.com/svn/trunk@15699 ce2b1a6d-e550-0410-aec6-3dcde31c8c00