git: openjdk/loom: fibers: New NotifyFramePop test to reproduce URL.openStream() issue

[duke]

Changeset: 54acea1b
Author:    Chris Plummer <chris.plummer at oracle.com>
Date:      2021-01-06 23:35:58 +0000
URL:       https://git.openjdk.java.net/loom/commit/54acea1b

New NotifyFramePop test to reproduce URL.openStream() issue

+ test/hotspot/jtreg/serviceability/jvmti/vthread/VThreadNotifyFramePopTest/VThreadNotifyFramePopTest.java
+ test/hotspot/jtreg/serviceability/jvmti/vthread/VThreadNotifyFramePopTest/libVThreadNotifyFramePopTest.cpp