VM: Type argument confusion for generic method with generic function typed parameter

[eernstg]

Consider the following program, which was executed with dart from c4af35c:

class A<X> {
  R f<R>(R Function<X>(A<X>) f) => f<X>(this);
}

main() {
  A<num> a = A<int>();
  print(a.f.runtimeType); // `dart` prints '<R>(<X>(A<R>) => R) => R'.
}

The type of A<int>().f should be R Function<R>(R Function<X>(A<X>)), but the printed text means R Function<R>(R Function<X>(A<R>)), so somehow the type parameter R of the method is used in a location where the type argument X of the parameter type should be.

Note that dart2js prints <T1>(<T2>(A<T2>) => T1) => T1, which is correct, so there must be some dart specific part to this.

Note the related issue #37381.