(Type u) is the old (Type (u+1))
(PType u) is the old (Type u)
Type* is the old (Type (_+1))
PType* is the old Type*
The stdlib can be compiled, but we still have > 70 broken tests
See discussion at #1341
We may fail to type check auxiliary definitions that use rec_fn_macro.
The problem is that this macro cannot be unfolded.
So, we fix the problem by not type checking them. We add them as
constants, and store the definition in an auxiliary vector.