git: openjdk/loom: fibers: update for JVMTI monitor functions to use VTMT and support cthreads

[duke]

Changeset: 6f9dc0d1
Author:    Serguei Spitsyn <serguei.spitsyn at oracle.com>
Date:      2020-10-17 10:39:55 +0000
URL:       https://git.openjdk.java.net/loom/commit/6f9dc0d1

update for JVMTI monitor functions to use VTMT and support cthreads

! src/hotspot/share/prims/jvmtiEnv.cpp
! src/hotspot/share/prims/jvmtiEnvBase.cpp
! test/hotspot/jtreg/serviceability/jvmti/vthread/VThreadMonitorTest/VThreadMonitorTest.java
! test/hotspot/jtreg/serviceability/jvmti/vthread/VThreadMonitorTest/libVThreadMonitorTest.c