javac should issue an error for this code:

value class C<T extends C> {
    void m(T t) {
        synchronized(t) {}
    }
}

as type variable T is bounded by a value class. Also this code should be rejected:

value class C<T extends C> {
    void foo(Object o) {
        synchronized ((C & I)o) {} // one of the superclasses of the intersection type is a value class
    }
}