RFR(XXS) 8203635: JFR sampler thread does not record stack info

[coleen.phillimore at oracle.com]

This looks good (and can count as trivial I think).
Coleen

On 5/22/18 1:40 PM, Zhengyu Gu wrote:
> Please review this trivial change that added 
> record_stack_base_and_size() call to JFR sampler thread, so NMT can 
> count it correctly.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8203635
> Webrev: http://cr.openjdk.java.net/~zgu/8203635/webrev.00/
>
> Test:
>   tier1_runtime on Linux 64
>
> Thanks,
>
> -Zhengyu
>
>
>