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

@@ -34,10 +34,16 @@
 public abstract class AbstractPointerStamp extends Stamp {
 
     private final boolean nonNull;
     private final boolean alwaysNull;
 
+    @Override
+    public void accept(Visitor v) {
+        v.visitBoolean(nonNull);
+        v.visitBoolean(alwaysNull);
+    }
+
     protected AbstractPointerStamp(boolean nonNull, boolean alwaysNull) {
         this.nonNull = nonNull;
         this.alwaysNull = alwaysNull;
     }