Add Guice hints when the only difference between two types is when one is a wildcard type and the other is a non-wildcard type that is mentioned in the extends/super clause of the wildcard type (e.g. Optional<Foo> vs. Optional<? extends Foo>).

Add Guice hints when the only difference between two types is when one is a wildcard type and the other is a non-wildcard type that is mentioned in the extends/super clause of the wildcard type (e.g. Optional<Foo> vs. Optional<? extends Foo>). #718