This includes performance improvements and backward incompatibility
fixes.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@67560 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
This includes performance improvement especially writing. Writing is
about 2 times faster.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66507 b2dd03c8-39d4-4d8f-98ff-823fe69b080e