git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@49295 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* common.mk (extract-gems): extract gem files to install them even if zlib is not available. git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@49271 b2dd03c8-39d4-4d8f-98ff-823fe69b080e