RFR 8171892: JShell: incorrect printing of multidemensional arrays

[Robert Field]

Please review...

Bugs:

     8171892: JShell: incorrect printing of multidemensional arrays
     https://bugs.openjdk.java.net/browse/JDK-8171892

     8171387: jshell tool: message inconsistencies
     https://bugs.openjdk.java.net/browse/JDK-8171387

Webrev:

     http://cr.openjdk.java.net/~rfield/8171892v0.webrev/

Thanks,
Robert