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

[Aleksey Shipilev]

On 05/22/2018 07:40 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/

Looks good to me. I wish this was handled in superclass initialization, so no one would miss this.

-Aleksey