Interpreter Demo Staff Instructions:

Starting with a fresh copy of the starter code, copy these files into the following places (possibly overwriting them):
build.xml
SamplePrograms/Example.java
src/Interpreter.java
src/AST/Visitor/InterpretVisitor.java
src/Scanner/minijava.jflex
src/Parser/minijava.cup

Run `ant demo-interpreter` to run the interpreter on the given Example.java