--- old/src/jdk.compiler/share/classes/com/sun/source/util/DocTreePathScanner.java	2020-07-23 09:48:38.498747851 -0700
+++ new/src/jdk.compiler/share/classes/com/sun/source/util/DocTreePathScanner.java	2020-07-23 09:48:38.082955836 -0700
@@ -39,6 +39,11 @@
  */
 public class DocTreePathScanner<R, P> extends DocTreeScanner<R, P> {
     /**
+     * Constructor for subclasses to call.
+     */
+    public DocTreePathScanner() {}
+
+    /**
      * Scans a tree from a position identified by a tree path.
      * @param path the path
      * @param p a value to be passed to visitor methods