Raw types crash in lub

[justmin]

Simple interface compilation produce exception with CF 2.1.6. Works good with CF 2.1.0

public interface TestClass {
    Class getRawClass();
    Class<?> getGenericClass();
    default Class<?> getWithArg(boolean generic){
        return generic ? getGenericClass() : getRawClass();
    }
}

[wmdietl]

Thanks for your report! I've added a test case that reproduces the problem at framework/tests/all-systems/Issue988.java.