A routine which prints `(agent {G}.is_stopable).generating_type' where
formal generic parameter G -> TEST2 displays FUNCTION [TEST2, TUPLE
[TEST2], BOOLEAN] but the actual generic parameter is TEST3 so this is
wrong.  An assignment attempt of `agent {G}.is_stopable' to a local of
type FUNCTION [G, TUPLE [G], BOOLEAN] assigns Void to the local, but
should not.

Discovered in release 5.5.0205.