Reland "Track the 'awaiter return' call stack..."

pkg/kernel/lib/transformations/async.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.
 
 library kernel.transformations.async;
 
 import '../kernel.dart';
 import 'continuation.dart';
 
 /// A transformer that introduces temporary variables for all subexpressions
@@ skipping 399 matching lines @@
     var shouldName = seenAwait;
     var result = new VariableGet(asyncResult);
 
     // The statements are in reverse order, so name the result first if
     // necessary and then add the two other statements in reverse.
     if (shouldName) result = name(result);
     statements.add(R.createContinuationPoint()..fileOffset = expr.fileOffset);
     Arguments arguments = new Arguments(<Expression>[
       expr.operand,
       new VariableGet(R.thenContinuationVariable),
-      new VariableGet(R.catchErrorContinuationVariable)
+      new VariableGet(R.catchErrorContinuationVariable),
+      new VariableGet(R.nestedClosureVariable),
     ]);
     statements.add(new ExpressionStatement(
         new StaticInvocation(R.helper.awaitHelper, arguments)
           ..fileOffset = expr.fileOffset));
 
     seenAwait = false;
     var index = nameIndex;
     arguments.positional[0] = expr.operand.accept(this)..parent = arguments;
 
     if (shouldName) nameIndex = index + 1;
@@ skipping 50 matching lines @@
       });
     }
   }
 
   visitFunctionNode(FunctionNode node) {
     var nestedRewriter =
         new RecursiveContinuationRewriter(continuationRewriter.helper);
     return node.accept(nestedRewriter);
   }
 }