Oilpan: We need to collect all garbage before shutting down the worker thread

Source/heap/HeapTest.cpp

Index: Source/heap/HeapTest.cpp
diff --git a/Source/heap/HeapTest.cpp b/Source/heap/HeapTest.cpp
index 86683ddd37c307f87d3c978a4fbe58d556c4c318..f6a2e354411c8465119d6ae526c066e565eb10fb 100644
--- a/Source/heap/HeapTest.cpp
+++ b/Source/heap/HeapTest.cpp
@@ -303,7 +303,6 @@ private:
             }
             yield();
         }
-        ThreadState::current()->cleanup();
         ThreadState::detach();
         atomicDecrement(&m_threadsToFinish);
     }