Re-add PositionedNode copy constructor for better backward compatibility

sablecc-runtime/src/main/java/de/hhu/stups/sablecc/patch/PositionedNode.java

@@ -19,6 +19,11 @@ public class PositionedNode {
     this(null, null);
   }
 
+  @Deprecated
+  public PositionedNode(final PositionedNode node) {
+    this(node.startPos, node.endPos);
+  }
+
   /**
    * Copies the {@link SourcePosition}s from the given node to this node.
    * This is an internal helper method for use in {@link Object#clone()} implementations.