gc/lock/jni/jnilock002 failed with an assert in the GC nightlies.

# Internal Error (/opt/jprt/T/P1/170716.jesper/s/hotspot/src/share/vm/runtime/synchronizer.cpp:1184), pid=11673, tid=139689563440896
# assert(ObjectSynchronizer::verify_objmon_isinpool(inf)) failed: monitor is invalid

Top of stack:
V [libjvm.so+0x107d4c1] VMError::report_and_die()+0x151;; VMError::report_and_die()+0x151
V [libjvm.so+0x73dc3b] report_vm_error(char const*, int, char const*, char const*)+0x7b;; report_vm_error(char const*, int, char const*, char const*)+0x7b
V [libjvm.so+0xfa562c] ObjectSynchronizer::inflate(Thread*, oop)+0x85c;; ObjectSynchronizer::inflate(Thread*, oop)+0x85c
V [libjvm.so+0xfa8508] ObjectSynchronizer::fast_enter(Handle, BasicLock*, bool, Thread*)+0x1c8;; ObjectSynchronizer::fast_enter(Handle, BasicLock*, bool, Thread*)+0x1c8
V [libjvm.so+0x9dcfc8] InterpreterRuntime::monitorenter(JavaThread*, BasicObjectLock*)+0x1c8;; InterpreterRuntime::monitorenter(JavaThread*, BasicObjectLock*)+0x1c8
j java.util.Vector.elementAt(I)Ljava/lang/Object;+0