RFC: @AuxCounters to expose some trivial user counters from the benchmarks

[Aleksey Shipilev]

(Nitsan, I think this is something you need for the queue experiments)

Hi,

I had committed the experimental API for exposing some trivial user
counters from the benchmarks. This JMH sample should be self-explanatory:
 http://hg.openjdk.java.net/code-tools/jmh/file/tip/jmh-samples/src/main/java/org/openjdk/jmh/samples/JMHSample_23_AuxCounters.java

Questions, suggestions, rants are welcome here. The API is really
constrained to special cases now. We can always modify, fix, or remove
this experimental part.

Thanks,
-Aleksey.