RFR (small) 8080357: JShell: Only unqualified unresolved references should be corralled

[Robert Field]

Bugs:
     https://bugs.openjdk.java.net/browse/JDK-8080357 <https://bugs.openjdk.java.net/browse/JDK-8080357>
     https://bugs.openjdk.java.net/browse/JDK-8081431 <https://bugs.openjdk.java.net/browse/JDK-8081431>

Webrev:
    http://cr.openjdk.java.net/~rfield/8080357v0.webrev/ <http://cr.openjdk.java.net/~rfield/8080357v0.webrev/>

Thanks,
Robert