Dart2js CPS: Implement 'await for'.

pkg/compiler/lib/src/cps_ir/cps_ir_builder.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.
 
 library dart2js.ir_builder;
 
 import '../closure.dart' as closure;
 import '../common.dart';
 import '../common/names.dart' show
     Names,
@@ skipping 1383 matching lines @@
             currentMask,
             emptyArguments));
     // TODO(johnniwinther): Extract this as a provided strategy.
     if (Elements.isLocal(variableElement)) {
       bodyBuilder.buildLocalVariableSet(variableElement, currentValue);
     } else if (Elements.isError(variableElement) ||
                Elements.isMalformed(variableElement)) {
       Selector selector = new Selector.setter(
           new Name(variableElement.name, variableElement.library));
       List<ir.Primitive> value = <ir.Primitive>[currentValue];
-      // Note the order of the comparisons below.  It can be the case that an
-      // element isError and isMalformed.
+      // Note the comparison below.  It can be the case that an element isError
+      // and isMalformed.
       if (Elements.isError(variableElement)) {
         bodyBuilder.buildStaticNoSuchMethod(selector, value);
       } else {
         bodyBuilder.buildErroneousInvocation(variableElement, selector, value);
       }
     } else if (Elements.isStaticOrTopLevel(variableElement)) {
       if (variableElement.isField) {
         bodyBuilder.addPrimitive(
             new ir.SetStatic(variableElement, currentValue));
       } else {
@@ skipping 1427 matching lines @@
                    this.stackTraceVariable,
                    this.buildCatchBlock});
 }
 
 class SwitchCaseInfo {
   final SubbuildFunction buildCondition;
   final SubbuildFunction buildBody;
 
   SwitchCaseInfo(this.buildCondition, this.buildBody);
 }