[Kernel] replace function debuggable field with originalAsyncMarker field

pkg/kernel/lib/transformations/continuation.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.continuation;
 
 import 'dart:math' as math;
 
 import '../ast.dart';
 import '../core_types.dart';
@@ skipping 803 matching lines @@
 
     // return :completer.future;
     var completerGet = new VariableGet(completerVariable);
     var returnStatement = new ReturnStatement(
         new PropertyGet(completerGet, new Name('future', helper.asyncLibrary)));
     statements.add(returnStatement);
 
     enclosingFunction.body = new Block(statements);
     enclosingFunction.body.parent = enclosingFunction;
     enclosingFunction.asyncMarker = AsyncMarker.Sync;
-    enclosingFunction.debuggable = false;
     return enclosingFunction;
   }
 
   Statement buildCatchBody(exceptionVariable, stackTraceVariable) {
     return new ExpressionStatement(new MethodInvocation(
         new VariableGet(completerVariable),
         new Name("completeError", helper.asyncLibrary),
         new Arguments([
           new VariableGet(exceptionVariable),
           new VariableGet(stackTraceVariable)
@@ skipping 135 matching lines @@
         findConstructor(syncIterableClass, ''),
         findConstructor(streamIteratorClass, ''),
         findFactoryConstructor(futureClass, 'microtask'),
         findConstructor(streamControllerClass, ''),
         findProcedure(asyncLibrary, '_asyncThenWrapperHelper'),
         findProcedure(asyncLibrary, '_asyncErrorWrapperHelper'),
         findProcedure(asyncLibrary, '_awaitHelper'),
         new CoreTypes(program));
   }
 }