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

@@ -41,10 +41,14 @@
 
     private VoidStamp() {
     }
 
     @Override
+    public void accept(Visitor v) {
+    }
+
+    @Override
     public Stamp unrestricted() {
         return this;
     }
 
     @Override