Version 3.21.5

Fixed compilation with recent MinGW64 versions. (issue 2300)

Added RemovePrototype to FunctionTemplate. (Chromium issue 272440)

Performance and stability improvements on all platforms.

git-svn-id: https://v8.googlecode.com/svn/trunk@16383 ce2b1a6d-e550-0410-aec6-3dcde31c8c00