Fix the obscure corner case of three items in a plural

pkg/intl/test/message_extraction/sample_with_messages.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /**
  * This is a program with various [Intl.message] messages. It just prints
  * all of them, and is used for testing of message extraction, translation,
  * and code generation.
  */
 library sample;
@@ skipping 132 matching lines @@
     printOut(thing.nonLambda());
     var x = YouveGotMessages.staticMessage();
     printOut(YouveGotMessages.staticMessage());
     printOut(notAlwaysTranslated());
     printOut(originalNotInBMP());
     printOut(escapable());
 
     printOut(thing.plurals(0));
     printOut(thing.plurals(1));
     printOut(thing.plurals(2));
+    printOut(thing.plurals(3));
+    printOut(thing.plurals(4));
+    printOut(thing.plurals(5));
+    printOut(thing.plurals(6));
+    printOut(thing.plurals(7));
+    printOut(thing.plurals(8));
+    printOut(thing.plurals(9));
+    printOut(thing.plurals(10));
+    printOut(thing.plurals(11));
+    printOut(thing.plurals(20));
+    printOut(thing.plurals(100));
+    printOut(thing.plurals(101));
+    printOut(thing.plurals(100000));
     var alice = new Person("Alice", "female");
     var bob = new Person("Bob", "male");
     var cat = new Person("cat", null);
     printOut(thing.whereTheyWent(alice, "house"));
     printOut(thing.whereTheyWent(bob, "house"));
     printOut(thing.whereTheyWent(cat, "litter box"));
     printOut(thing.nested([alice, bob], "magasin"));
     printOut(thing.nested([alice], "magasin"));
     printOut(thing.nested([], "magasin"));
     printOut(thing.nested([bob, bob], "magasin"));
@@ skipping 17 matching lines @@
   var fr = new Intl("fr");
   var english = new Intl("en_US");
   var de = new Intl("de_DE");
   // Throw in an initialize of a null locale to make sure it doesn't throw.
   initializeMessages(null);
   var f1 = initializeMessages(fr.locale).then((_) => printStuff(fr));
   var f2 = initializeMessages(de.locale).then((_) => printStuff(de));
   printStuff(english);
   return Future.wait([f1, f2]);
 }