增加AST结构

git-svn-id: https://qlanguage.googlecode.com/svn/trunk@214 6d982bb3-a5a7-393d-ffc5-582415be9c85
修正编译失败

git-svn-id: https://qlanguage.googlecode.com/svn/trunk@215 6d982bb3-a5a7-393d-ffc5-582415be9c85