8189360: JvmtiExport::weak_oops_do is called for all JNIHandleBlock instances

[Kim Barrett]

> On Oct 18, 2017, at 8:01 AM, Stefan Karlsson <stefan.karlsson at oracle.com> wrote:
> New webrevs:
> http://cr.openjdk.java.net/~stefank/8189360/webrev.01.delta
> http://cr.openjdk.java.net/~stefank/8189360/webrev.01

Looks good.