RFR 8165372 : StackWalker performance regression following JDK-8147039

[Mandy Chung]

> On Sep 19, 2016, at 12:35 PM, Brent Christian <brent.christian at oracle.com> wrote:
> 
> Hi,
> 
> Please review my fix for 8165372 : "StackWalker performance regression following JDK-8147039"
> 
> Bug: https://bugs.openjdk.java.net/browse/JDK-8165372
> Webrev: http://cr.openjdk.java.net/~bchristi/8165372/webrev.00/
> 

This looks good and clean.  I have the same comment what Coleen pointed out:
  + if (need_method_info(mode) == false && get_caller_class(mode) &&

and Handle stackFrame.

Mandy