--- old/src/java.compiler/share/classes/javax/tools/DiagnosticCollector.java	2019-09-08 19:55:24.828001000 -0700
+++ new/src/java.compiler/share/classes/javax/tools/DiagnosticCollector.java	2019-09-08 19:55:24.688001000 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2006, 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2006, 2019, 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
@@ -43,6 +43,11 @@
     private List<Diagnostic<? extends S>> diagnostics =
             Collections.synchronizedList(new ArrayList<Diagnostic<? extends S>>());
 
+    /**
+     * Creates a new instance of DiagnosticCollector.
+     */
+    public DiagnosticCollector() {}
+
     public void report(Diagnostic<? extends S> diagnostic) {
         Objects.requireNonNull(diagnostic);
         diagnostics.add(diagnostic);