hg: jdk/submit: 8223177: Data race on JvmtiEnvBase::_tag_map in double-checked locking

[manc at google.com]

Changeset: 5bd5fe29de95
Author:    manc
Date:      2019-04-30 18:44 -0700
URL:       http://hg.openjdk.java.net/jdk/submit/rev/5bd5fe29de95

8223177: Data race on JvmtiEnvBase::_tag_map in double-checked locking
Summary: Add memory fences on accesses to JvmtiEnvBase::_tag_map
Reviewed-by:

! src/hotspot/share/prims/jvmtiEnvBase.hpp
! src/hotspot/share/prims/jvmtiTagMap.cpp