ART: Register object tagging table

Actually register object tagging table with the runtime so it
gets swept properly.

Bug: 31385027
Test: m test-art-host
Test: m ART_USE_READ_BARRIER=true test-art-host
Change-Id: I4364458ece2893e6a85fe7518df39fb838199f20
diff --git a/runtime/openjdkjvmti/OpenjdkJvmTi.cc b/runtime/openjdkjvmti/OpenjdkJvmTi.cc
index bebc2fc..bea40c8 100644
--- a/runtime/openjdkjvmti/OpenjdkJvmTi.cc
+++ b/runtime/openjdkjvmti/OpenjdkJvmTi.cc
@@ -1035,7 +1035,9 @@
 
 // The plugin initialization function. This adds the jvmti environment.
 extern "C" bool ArtPlugin_Initialize() {
-  art::Runtime::Current()->GetJavaVM()->AddEnvironmentHook(GetEnvHandler);
+  art::Runtime* runtime = art::Runtime::Current();
+  runtime->GetJavaVM()->AddEnvironmentHook(GetEnvHandler);
+  runtime->AddSystemWeakHolder(&gObjectTagTable);
   return true;
 }