RFR: JDK-7123493 : (proxy) Proxy.getProxyClass doesn't scale under high load

[Rob McKenna]

Hi folks,

Looking to backport this fix to JDK7. The backport has resulted in 
relatively minor changes to the original fix such as replicating the 
BiFunction / Supplier interfaces in a limited sense as inner classes in 
WeakCache.

http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7123493
Original review thread: 
http://mail.openjdk.java.net/pipermail/core-libs-dev/2013-April/015854.html

     -Rob