git: openjdk/loom: preempt-support: Use counter to disable preemption + add new run to VThreadPreemption.java

[duke]

Changeset: 04504f3c
Author:    Patricio Chilano Mateo <patricio.chilano.mateo at oracle.com>
Date:      2023-04-11 13:40:43 +0000
URL:       https://git.openjdk.org/loom/commit/04504f3c84f59ea014e9d78245b105c33d5032d9

Use counter to disable preemption + add new run to VThreadPreemption.java

! src/hotspot/share/classfile/javaClasses.cpp
! src/hotspot/share/classfile/javaClasses.hpp
! src/hotspot/share/prims/jvmtiExport.cpp
! src/hotspot/share/runtime/continuation.cpp
! src/hotspot/share/runtime/continuation.hpp
! src/hotspot/share/runtime/continuationFreezeThaw.cpp
! src/hotspot/share/runtime/interfaceSupport.cpp
! src/java.base/share/classes/java/lang/VirtualThread.java
! test/hotspot/jtreg/serviceability/jvmti/vthread/VThreadPreemption/VThreadPreemption.java