Remove default constructors from java.compiler

Summary

Add explicit constructors to two classes in the java.compiler module relying on default constructors.

Problem

Formal classes relying on default constructors.

Solution

Add explicit constructors to the classes in question.

Specification

--- 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);
--- old/src/java.compiler/share/classes/javax/tools/ToolProvider.java    2019-09-08 19:55:25.164001000 -0700
+++ new/src/java.compiler/share/classes/javax/tools/ToolProvider.java    2019-09-08 19:55:25.032001000 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 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
@@ -45,6 +45,12 @@
     private static final String systemJavaCompilerName   = "com.sun.tools.javac.api.JavacTool";

     /**
+     * Do not call.
+     */
+    @Deprecated(forRemoval=true, since="14")
+    public ToolProvider() {}
+
+    /**
      * Returns the Java&trade; programming language compiler provided
      * with this platform.
      * <p>The file manager returned by calling