Proposed API for JEP 259: Stack-Walking API

[Mandy Chung]

JEP 259:  http://openjdk.java.net/jeps/259

Javadoc for the proposed StackWalker API:
   http://cr.openjdk.java.net/~mchung/jdk9/jep259/api/java/lang/StackWalker.html

A simple way to walk the stack:

   StackWalker walker = new StackWalker(StackWalker.Option.CLASS_REFERENCE);
   walker.walk((s) ->  s.filter(f -> interestingClasses.contains(f.getDeclaringClass())).findFirst());

The current usage of sun.reflect.Reflection.getCallerClass(int depth) can be replaced with this StackWalker API.

Any feedback on the proposed API is appreciated.

Mandy

P.S. webrev of the current implementation:
   http://cr.openjdk.java.net/~mchung/jdk9/jep259/webrev.00/