Remove sun.misc.CompoundEnumeration

[Chris Hegarty]

sun.misc.CompoundEnumeration is a utility class that supports enumerating
over an array of enumerations. It is used in just a single place in the JDK, in
ClassLoader.getResources(String) to support enumerating over the parent’s
resources as well as the current loaders resources. I can find no usages
outside of the JDK.

This issue proposes to move sun.mics.CompoundEnumeration and its only
use-site, in ClassLoader.

http://cr.openjdk.java.net/~chegar/8146000/

Thanks,
-Chris.

P.S. this change has been prompted by preparatory cleanup work for
JEP 260, JDK-8132928.