RFR 8221623 : Add StackWalker micro benchmarks to jdk repo

[Brent Christian]

Hi,

Please review these StackWalker and Throwable benchmarks for addition 
into the JDK microbenchmarks.

Bug:
https://bugs.openjdk.java.net/browse/JDK-8221623
Webrev:
http://cr.openjdk.java.net/~bchristi/8221623/webrev07/

The StackWalker benchmarks use StackWalker's forEach(), walk(), and 
Options to measure retrieval of various types of information from the 
call stack.

The Throwable benchmarks do corresponding exercises; there are also a 
couple of Logging benchmarks.

A JMH @Param is used to test a variety of call stack depths.


In the future, we might consider a benchmark for 
Reflection.getCallerClass().  (It is more involved today to benchmark 
that method than at the time these benchmarks were originally written, 
so that one's commented out.) See JDK-8230976.

Thanks,
-Brent

1. https://bugs.openjdk.java.net/browse/JDK-8230976