RFR 8081219: hs_err improvement: Add event logging for class redefinition to the hs_err file

[Coleen Phillimore]

Summary: Use the Events::log function to save redefined classes for 
output to the hs_err file.

This change adds lines to the hs_err_pid file which names classes redefined:

Classes redefined (2 events):
Event: 11.867 Thread 0x00007fd378199800 redefined class 
name=RedefineRunningMethods$B, count=1
Event: 26.746 Thread 0x00007fd378199800 redefined class 
name=RedefineRunningMethods$B, count=2

Tested with intentional crash to see hs_err_pid files, also tested 
without intentional crashes vm.redefine.testlist.

open webrev at http://cr.openjdk.java.net/~coleenp/8081219/
bug link https://bugs.openjdk.java.net/browse/JDK-8081219

Thanks,
Coleen