Review request for JDK-8139269: Do not expose prune method handles from ChainedCallSite

[Attila Szegedi]

Please review JDK-8139269 "Do not expose prune method handles from 
ChainedCallSite" at <http://cr.openjdk.java.net/~attila/8139269/webrev.jdk9> 
for <https://bugs.openjdk.java.net/browse/JDK-8139269>

Thanks,
  Attila.