Checkpoint:
  Throw when an attempt is made to construct an instance of an open generic type.
  Make JSIL.AbstractEnumerator and JSIL.AbstractEnumerable generic types
  Update the LINQ stubs to use the new interface API
Checkpoint:
  Fix type qualified properties in nested types
Checkpoint:
  Implement overloaded interface method invocations
Checkpoint:
  Calling a method of an open generic interface throws.
  Always rebind InterfaceMethod objects when an interface goes from open to closed.
  Fix packed struct arrays.
  It turns out the MethodReference class is incredibly broken in a very, very stupid way, so add a workaround.