8325485: IncrementInstructions.of(int, int) is not storing the args

Reviewed-by: liach, jlahoda

src/java.base/share/classes/jdk/internal/classfile/impl/AbstractInstruction.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2022, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -860,7 +860,7 @@ public abstract sealed class AbstractInstruction
 
         @Override
         public int constant() {
-            return 0;
+            return constant;
         }
 
         @Override