hg: jdk/jdk: 8212958: Allow Klass::_subklass and _next_sibling to have unloaded classes

[coleen.phillimore at oracle.com]

Changeset: 274ba8fbd96d
Author:    coleenp
Date:      2018-10-29 10:21 -0400
URL:       http://hg.openjdk.java.net/jdk/jdk/rev/274ba8fbd96d

8212958: Allow Klass::_subklass and _next_sibling to have unloaded classes
Summary: Don't return unloaded klasses. Make sure access is protected by Compile_lock.
Reviewed-by: eosterlund, dlong

! src/hotspot/share/ci/ciInstanceKlass.cpp
! src/hotspot/share/ci/ciInstanceKlass.hpp
! src/hotspot/share/jfr/jni/jfrGetAllEventClasses.cpp
! src/hotspot/share/jvmci/jvmciCompilerToVM.cpp
! src/hotspot/share/memory/universe.cpp
! src/hotspot/share/memory/universe.hpp
! src/hotspot/share/oops/instanceKlass.cpp
! src/hotspot/share/oops/instanceKlass.hpp
! src/hotspot/share/oops/klass.cpp
! src/hotspot/share/oops/klass.hpp
! src/hotspot/share/runtime/mutex.cpp
! src/hotspot/share/utilities/vmError.cpp
+ test/hotspot/jtreg/runtime/ClassUnload/UnloadInterfaceTest.java
+ test/hotspot/jtreg/runtime/ClassUnload/test/ImplementorClass.java
+ test/hotspot/jtreg/runtime/ClassUnload/test/Interface.java
! test/hotspot/jtreg/runtime/testlibrary/ClassUnloadCommon.java