Make EventBinding a context heap boundary.

Author: jchalou

truffle/src/com.oracle.truffle.polyglot/src/com/oracle/truffle/polyglot/ObjectSizeCalculator.java

@@ -72,6 +72,7 @@
 import com.oracle.truffle.api.dsl.NodeFactory;
 import com.oracle.truffle.api.impl.DefaultTruffleRuntime;
 import com.oracle.truffle.api.instrumentation.AllocationReporter;
+import com.oracle.truffle.api.instrumentation.EventBinding;
 import com.oracle.truffle.api.instrumentation.ExecutionEventListener;
 import com.oracle.truffle.api.instrumentation.TruffleInstrument;
 import com.oracle.truffle.api.io.TruffleProcessBuilder;
@@ -350,6 +351,8 @@ private static boolean isContextHeapBoundary(APIAccess api, Object obj) {
 
                         (obj instanceof ContextLocal) ||
                         (obj instanceof ContextThreadLocal) ||
+
+                        (obj instanceof EventBinding<?>) ||
                         /*
                          * For safety, copy the asserts here in case asserts are disabled.
                          */