HKTypeLambda variations: test all of these

[Jamie Thompson]

[[T] =>> Map[T, Int]]
[F[X] <: Either[X, Int]]
[F1[X] >: F[X]] where +F[_] is already declared
[H[F[X]] <: Foo[F[X]]] and
[G[F[X]] >: Bar[F[X]]]
[F[_] <: Qux[_,Int] or perhaps [F[_] <: Qux[_,_]?
[F[X] >: [Z] =>> List[Z] <: [Y] =>> List[Y]]