Add safety check to dynalink inner class lookup

The fix for JDK-8210943 assumes the classes returned by java.lang.Classes#getClasses() to be ordered by declaring class, going from subclass to superclass. While this is the case with the current implementation, this is not guaranteed by the API specification, so we should add additional checks to make sure we pick the right class if the method returns classes with the same name.

http://mail.openjdk.java.net/pipermail/nashorn-dev/2018-December/007451.html