8022836: JVM crashes in JVMTIENVBASE::GET_CURRENT_CONTENDED_MONITOR and GET_OWNED_MONITOR
Summary: Check that the _java_thread parameter is valid when it is possible that the JavaThread has exited after the initial checks were made in generated/jvmtifiles/jvmtiEnter.cpp: jvmti_GetCurrentContendedMonitor()
Reviewed-by: dcubed, dsamersoff
8024826: (s) : Remove alt-rt.jar, used by +AggressiveOps
Reviewed-by: alanb, chegar, dholmes, ksrini
Contributed-by: Mike Duigou <mike.duigou@oracle.com>