--- old/src/jdk.compiler/share/classes/com/sun/source/util/TreePathScanner.java	2020-07-23 09:48:41.721135968 -0700
+++ new/src/jdk.compiler/share/classes/com/sun/source/util/TreePathScanner.java	2020-07-23 09:48:41.257367951 -0700
@@ -43,6 +43,10 @@
  * @since 1.6
  */
 public class TreePathScanner<R, P> extends TreeScanner<R, P> {
+    /**
+     * Constructor for subclasses to call.
+     */
+    public TreePathScanner() {}
 
     /**
      * Scans a tree from a position identified by a TreePath.