Re-enable Yaml tests on dart2js and dartc.

utils/pub/yaml/parser.dart

 // Copyright (c) 2012, 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.
 
 /**
  * Translates a string of characters into a YAML serialization tree.
  *
  * This parser is designed to closely follow the spec. All productions in the
  * spec are numbered, and the corresponding methods in the parser have the same
  * numbers. This is certainly not the most efficient way of parsing YAML, but it
@@ skipping 230 matching lines @@
    */
   List oneOrMore(consumer()) {
     var first = consumer();
     if (!truth(first)) return null;
     var out = [first];
     while (true) {
       var el = consumer();
       if (!truth(el)) return out;
       out.add(el);
     }
+    return null; // unreachable

[Bob Nystrom, 2012/05/24 22:36:50]

"Unreachable."

   }
 
   /**
    * Calls [consumer] until it returns a falsey value. Returns a list of all
    * truthy return values of [consumer], or the empty list if it didn't consume
    * anything.
    *
    * Conceptually, repeats a production any number of times.
    */
   List zeroOrMore(consumer()) {
     var out = [];
     var oldPos = pos;
     while (true) {
       var el = consumer();
       if (!truth(el) || oldPos == pos) return out;
       oldPos = pos;
       out.add(el);
     }
+    return null; // unreachable
   }
 
   /**
    * Just calls [consumer] and returns its result. Used to make it explicit that
    * a production is intended to be optional.
    */
   zeroOrOne(consumer()) => consumer();
 
   /**
    * Calls each function in [consumers] until one returns a truthy value, then
@@ skipping 1552 matching lines @@
     s_l_comments();
     return doc;
   }
 
   // 209
   _Node l_directiveDocument() {
     if (!truth(oneOrMore(l_directive))) return null;
     var doc = l_explicitDocument();
     if (doc != null) return doc;
     parseFailed();
+    return null; // unreachable
   }
 
   // 210
   _Node l_anyDocument() =>
     or([l_directiveDocument, l_explicitDocument, l_bareDocument]);
 
   // 211
   List<_Node> l_yamlStream() {
     var docs = [];
     zeroOrMore(l_documentPrefix);
@@ skipping 40 matching lines @@
 
 /** The information in the header for a block scalar. */
 class _BlockHeader {
   final int additionalIndent;
   final int chomping;
 
   _BlockHeader(this.additionalIndent, this.chomping);
 
   bool get autoDetectIndent() => additionalIndent == null;
 }