This branch removes support for the
RankNTypes language extension and its changes to the AST (e.g. by reintroducing
The idea here is to defer support for higher-rank polymorphism due to longer-standing issues in the frontend (see curry-frontend#77) and focus on having a stable main version of the frontend again.
A future merge request could re-revert these changes to include higher-rank-polymorphism support again.