Implement async/await/yield and async for-in

pkg/compiler/lib/src/ssa/kernel_ast_adapter.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 file.
 
 import 'package:js_runtime/shared/embedded_names.dart';
 import 'package:kernel/ast.dart' as ir;
 
 import '../common.dart';
 import '../common/names.dart';
 import '../compiler.dart';
@@ skipping 387 matching lines @@
       TypeMaskFactory.inferredReturnTypeForElement(
           _backend.helpers.exceptionUnwrapper, _globalInferenceResults);
 
   ir.Procedure get traceFromException =>
       kernel.functions[_backend.helpers.traceFromException];
 
   TypeMask get traceFromExceptionType =>
       TypeMaskFactory.inferredReturnTypeForElement(
           _backend.helpers.traceFromException, _globalInferenceResults);
 
+  ir.Procedure get streamIteratorConstructor =>
+      kernel.functions[_backend.helpers.streamIteratorConstructor];
+
+  TypeMask get streamIteratorConstructorType =>
+      TypeMaskFactory.inferredReturnTypeForElement(
+          _backend.helpers.streamIteratorConstructor, _globalInferenceResults);
+
   ir.Procedure get mapLiteralUntypedMaker =>
       kernel.functions[_backend.helpers.mapLiteralUntypedMaker];
 
   MemberElement get jsIndexableLength => _backend.helpers.jsIndexableLength;
 
   ir.Procedure get checkConcurrentModificationError =>
       kernel.functions[_backend.helpers.checkConcurrentModificationError];
 
   TypeMask get checkConcurrentModificationErrorReturnType =>
       TypeMaskFactory.inferredReturnTypeForElement(
@@ skipping 39 matching lines @@
   ir.Procedure get createRuntimeType =>
       kernel.functions[_backend.helpers.createRuntimeType];
 
   TypeMask get createRuntimeTypeReturnType =>
       TypeMaskFactory.inferredReturnTypeForElement(
           _backend.helpers.createRuntimeType, _globalInferenceResults);
 
   ir.Class get objectClass =>
       kernel.classes[_compiler.commonElements.objectClass];
 
+  ir.Class get futureClass =>
+      kernel.classes[_compiler.commonElements.futureClass];
+
+  TypeMask makeSubtypeOfObject(ClosedWorld closedWorld) =>
+      new TypeMask.subclass(_compiler.commonElements.objectClass, closedWorld);
+
   ir.Procedure get currentIsolate =>
       kernel.functions[_backend.helpers.currentIsolate];
 
   ir.Procedure get callInIsolate =>
       kernel.functions[_backend.helpers.callInIsolate];
 
   bool isInForeignLibrary(ir.Member member) =>
       _backend.isForeign(getElement(member));
 
   native.NativeBehavior getNativeBehavior(ir.Node node) {
@@ skipping 487 matching lines @@
 
   @override
   String get name => null;
 
   @override
   int get nestingLevel => 1;
 
   @override
   ast.Node get statement => null;
 }