Please review JDK-8168005 "Introduce namespaces for GET, SET Dynalink operations" at <http://cr.openjdk.java.net/~attila/8168005/webrev.jdk9> for <https://bugs.openjdk.java.net/browse/JDK-8168005>
The JIRA issue has detailed rationale for the change. The diff is moderately large, but the Dynalink API changes are only a part of it, the rest is adjusting Nashorn, code examples, and tests to the changed API. Thanks, Attila.