With generic class Class, there is a compatibility problem
in code such as

    Class c = b ? A.class : B.class;

This would be illegal (neither Class<A> nor Class<B>
is a subtype of the other). We propose to resolve this using the same
algorithm we use for type inference of a call to a method whose signature is

    <T> T f(boolean b, T t1, T t2);

Using the wildcard notation, the type of the right-hand-side of the
assignment above is Class<?>, which is compatible with raw Class, so
the assignment as a whole succeeds.