Add builtin, fix group and order

src/qir/ast/QIRBuiltin.java

src/qir/ast/operator/QIRGroup.java

src/qir/ast/operator/QIROrder.java

src/qir/ast/value/QIRDouble.java

src/qir/driver/SQLStringDriver.java

src/qir/visitor/IQIRVisitor.java

src/qir/visitor/QIRCompileVisitor.java

src/qir/visitor/QIREvaluationVisitor.java

src/qir/visitor/QIRFreeVarsVisitor.java

src/qir/visitor/QIRGreedyReduceVisitor.java

src/qir/visitor/QIRSQLStringVisitor.java