Fix copy-paste issues and address TODOs

diff --git a/src/jdk.compiler/share/classes/com/sun/source/tree/YieldTree.java b/src/jdk.compiler/share/classes/com/sun/source/tree/YieldTree.java
index ae82c72b4a3..181d0495774 100644
--- a/src/jdk.compiler/share/classes/com/sun/source/tree/YieldTree.java
+++ b/src/jdk.compiler/share/classes/com/sun/source/tree/YieldTree.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2019, 2020, 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
@@ -33,7 +33,7 @@ package com.sun.source.tree;
  * yield <em>expression</em> ;
  * </pre>
  *
- * @jls section TODO
+ * @jls 14.21 The yield Statement
  *
  * @since 13
  */
diff --git a/src/jdk.compiler/share/classes/com/sun/source/util/DocTreeScanner.java b/src/jdk.compiler/share/classes/com/sun/source/util/DocTreeScanner.java
index 631bac627e0..0ed59fe31b4 100644
--- a/src/jdk.compiler/share/classes/com/sun/source/util/DocTreeScanner.java
+++ b/src/jdk.compiler/share/classes/com/sun/source/util/DocTreeScanner.java
@@ -275,7 +275,7 @@ public class DocTreeScanner<R,P> implements DocTreeVisitor<R,P> {
     }
 
     /**
- * {@inheritDoc} This implementation returns {@code null}.
+ * {@inheritDoc} This implementation scans the children in left to right order.
      *
      * @param node {@inheritDoc}
      * @param p {@inheritDoc}
diff --git a/src/jdk.compiler/share/classes/com/sun/source/util/TreeScanner.java b/src/jdk.compiler/share/classes/com/sun/source/util/TreeScanner.java
index 46d173f5ba2..e7cff68e384 100644
--- a/src/jdk.compiler/share/classes/com/sun/source/util/TreeScanner.java
+++ b/src/jdk.compiler/share/classes/com/sun/source/util/TreeScanner.java
@@ -950,7 +950,7 @@ public class TreeScanner<R,P> implements TreeVisitor<R,P> {
     }
 
     /**
- * {@inheritDoc} This implementation returns {@code null}.
+ * {@inheritDoc} This implementation scans the children in left to right order.
      *
      * @param node {@inheritDoc}
      * @param p {@inheritDoc}