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

*** 46,55 ****
--- 46,62 ----
          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);