src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.core.common/src/org/graalvm/compiler/core/common/type/AbstractObjectStamp.java

@@ -46,10 +46,17 @@
         super(nonNull, alwaysNull);
         this.type = type;
         this.exactType = exactType;
     }
 
+    @Override
+    public void accept(Visitor v) {
+        super.accept(v);
+        v.visitObject(type);
+        v.visitBoolean(exactType);
+    }
+
     protected abstract AbstractObjectStamp copyWith(ResolvedJavaType newType, boolean newExactType, boolean newNonNull, boolean newAlwaysNull);
 
     @Override
     protected final AbstractPointerStamp copyWith(boolean newNonNull, boolean newAlwaysNull) {
         return copyWith(type, exactType, newNonNull, newAlwaysNull);