Update dart2js to fix #80.

lib/kernel.dart

 // Copyright (c) 2016, 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.md file.
 
 library rasta.kernel;
 
 import 'dart:async' show
     Future;
 
 import 'dart:collection' show
@@ skipping 65 matching lines @@
   final Map<FieldElement, ir.Field> fields = <FieldElement, ir.Field>{};
 
   final Map<TypeVariableElement, ir.TypeParameter> typeParameters =
       <TypeVariableElement, ir.TypeParameter>{};
 
   final Map<TypeVariableElement, ir.TypeParameter> factoryTypeParameters =
       <TypeVariableElement, ir.TypeParameter>{};
 
   final Set<ir.TreeNode> checkedNodes = new Set<ir.TreeNode>();
 
-  final Map<String, int> mixinApplicationNames = <String, int>{};
+  final Map<LibraryElement, Map<String, int>> mixinApplicationNamesByLibrary =
+      <LibraryElement, Map<String, int>>{};
 
   /// FIFO queue of work that needs to be completed before the returned AST
   /// nodes are correct.
   final Queue<WorkItem> workQueue = new Queue<WorkItem>();
 
   Kernel(this.compiler);
 
   bool hasMainMethod(Uri uri) {
     LibraryElement library = compiler.libraryLoader.lookupLibrary(uri);
     return library.localLookup("main") != null;
@@ skipping 81 matching lines @@
       return libraryNode;
     });
   }
 
   /// Compute a name for [cls]. We want to have unique names in a library, but
   /// mixin applications can lead to multiple classes with the same name. So
   /// for those we append `#` and a number.
   String computeName(ClassElement cls) {
     String name = cls.name;
     if (!cls.isUnnamedMixinApplication) return name;
+    Map<String, int> mixinApplicationNames =
+        mixinApplicationNamesByLibrary.putIfAbsent(
+            cls.library.implementation, () => <String, int>{});
     mixinApplicationNames.putIfAbsent(name, () => 0);

[kasperl, 2016/07/01 13:05:14]

int count = mixinApplicationNames.putIfAbsent(name, () => 0);
mixinApplicationNames[name] = count + 1;
return "$name#$count";

is an alternative.

[ahe, 2016/07/01 13:14:15]

I like that better.

     int count = mixinApplicationNames[name]++;
     return "$name#$count";
   }
 
   ir.Class classToIr(ClassElement cls) {
     cls = cls.declaration;
     return classes.putIfAbsent(cls, () {
       cls.ensureResolved(compiler.resolution);
       compiler.enqueuer.resolution.emptyDeferredTaskQueue();
       String name = computeName(cls);
@@ skipping 456 matching lines @@
 }
 
 class ConstructorTarget {
   final ConstructorElement element;
   final DartType type;
 
   ConstructorTarget(this.element, this.type);
 
   String toString() => "ConstructorTarget($element, $type)";
 }