Add handle wrapper to allocation listener

Fix failing test for interpreter.

Test: mm -j32 test-art-host-run-test-debug-prebuild-interpreter-relocate-trace-cms-checkjni-picimage-npictest-ndebuggable-904-object-allocation32  ART_TEST_TRACE=true ART_TEST_OPTIMIZING=false ART_TEST_INTERPRETER=true

Change-Id: I9e7e09db82cf13730dc2471ac05260bf6a69ab7c
diff --git a/runtime/openjdkjvmti/events.cc b/runtime/openjdkjvmti/events.cc
index 7e4ee84..450f85e 100644
--- a/runtime/openjdkjvmti/events.cc
+++ b/runtime/openjdkjvmti/events.cc
@@ -133,6 +133,8 @@
     DCHECK_EQ(self, art::Thread::Current());
 
     if (handler_->IsEventEnabledAnywhere(JVMTI_EVENT_VM_OBJECT_ALLOC)) {
+      art::StackHandleScope<1> hs(self);
+      auto h = hs.NewHandleWrapper(obj);
       // jvmtiEventVMObjectAlloc parameters:
       //      jvmtiEnv *jvmti_env,
       //      JNIEnv* jni_env,