Do more CSE when flattening binary operators
Do more CSE when flattening binary operators

tias/libminizinc,jjdekker/libminizinc,nathanielbaxter/libminizinc,nathanielbaxter/libminizinc,jjdekker/libminizinc,jjdekker/libminizinc,jjdekker/libminizinc,tias/libminizinc,nathanielbaxter/libminizinc,nathanielbaxter/libminizinc