After initial compilation, the type of an entity in a generic class is
changed from `FOO [G]' (where G is the name of the formal parameter of
the enclosing generic class) to `FOO [STRING], thereby introducing a
VEEN error.  When the system is recompiled, the compiler does not
detect the error, but only if a generic generic constraint is also
added to the single formal generic parameter of FOO.

Discovered in Release 3.2.4.