RFR(M): 8165550: Add class loader names to ClassCastException message

[Rachel Protacio]

Hi,

Please review this Jigsaw enhancement which adds the new format of class 
loader names to VM ClassCastException messages. Includes an 
updated/expanded jtreg test.

Bug: https://bugs.openjdk.java.net/browse/JDK-8165550
Open webrev: http://cr.openjdk.java.net/~rprotacio/8165550.00/

Passes JPRT and jck vm and lang tests.

Thanks!
Rachel