RFR 9: 8078099 : (process) ProcessHandle should uniquely identify processes

Please review changes to ProcessHandle implementation to uniquely identify processes based on the start time provided by the OS. It addresses the issue of PID reuse. This is the implementation of the ProcessHandle.equals() spec change in 8129344 : (process) ProcessHandle instances should define equals and be value-based Webrev: http://cr.openjdk.java.net/~rriggs/webrev-starttime-8078099/ Issue: https://bugs.openjdk.java.net/browse/JDK-8078099 Thanks, Roger