[Patch] Pass counter values to -prof perf

[Eric Caspole]

Hi everybody,

I have a use case with JMH on new hardware where I need to pass the 
counters I want to see to -prof perf, I would like to contribute a patch 
for this below:

  http://cr.openjdk.java.net/~ecaspole/jmh_stat_counters/webrev/

It works like -prof perfasm extended syntax like

  -prof 'perf:events=cycles,instructions,r99'

Works for me so far in my own case here.

Thanks,

Eric