Fix typechecking
Rewrite AST generation
Squash AST generation bug
Typecheck IntExprs
Fix the rest of the failing test cases
Codegen: variable declaration and initialization
Codegen: intexprs
Handle stack overflow
Fix AST generation bug
Codegen: backpatching and printstmts
Codegen: ifs and boolexprs
Test cases and assorted bugfixes
Print boolvals properly
Print boolean type variables properly
Print boolean expressions properly