Big merge from experimental to bleeding edge.

sdk/lib/_internal/compiler/implementation/compiler.dart

Index: sdk/lib/_internal/compiler/implementation/compiler.dart
diff --git a/sdk/lib/_internal/compiler/implementation/compiler.dart b/sdk/lib/_internal/compiler/implementation/compiler.dart
index e16fe4e9b8e2de1d8694a1ad27cb683ae334808e..dc77762d69ab09d22ee9220bc78c411285ca4f28 100644
--- a/sdk/lib/_internal/compiler/implementation/compiler.dart
+++ b/sdk/lib/_internal/compiler/implementation/compiler.dart
@@ -537,6 +537,7 @@ abstract class Compiler implements DiagnosticListener {
     bool nativeTest = library.entryCompilationUnit.script.name.contains(
         'dart/tests/compiler/dart2js_native');
     if (nativeTest
+        || libraryName == 'dart:async'
         || libraryName == 'dart:mirrors'
         || libraryName == 'dart:math'
         || libraryName == 'dart:html'
@@ -567,7 +568,10 @@ abstract class Compiler implements DiagnosticListener {
   void maybeEnableIsolateHelper(LibraryElement library) {
     String libraryName = library.uri.toString();
     if (libraryName == 'dart:isolate'
-        || libraryName == 'dart:html') {
+        || libraryName == 'dart:html'
+        // TODO(floitsch): create a separate async-helper library instead of
+        // importing the isolate-library just for async.
+        || libraryName == 'dart:async') {
       importIsolateHelperLibrary(library);
     }
   }