Remove Fasta's copy of accessors.dart.

pkg/kernel/lib/transformations/closure/context.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.closure.context;
 
 import '../../ast.dart'
     show
         Arguments,
         Class,
         Expression,
         IntLiteral,
         MethodInvocation,
         Name,
         NullLiteral,
         PropertyGet,
         StringLiteral,
         Throw,
+        TreeNode,
         VariableDeclaration,
         VariableGet,
         VariableSet;
 
 import '../../frontend/accessors.dart'
     show Accessor, IndexAccessor, VariableAccessor;
 
 import 'converter.dart' show ClosureConverter;
 
 abstract class Context {
@@ skipping 91 matching lines @@
     assert(contextClass.constructors.length == 1);
     converter.rewriter
         .insertContextDeclaration(contextClass, parent.expression);
 
     return new LocalContext._internal(converter, parent,
         converter.rewriter.contextDeclaration, converter.rewriter.contextSize);
   }
 
   Expression get expression => accessor.buildSimpleRead();
 
-  Accessor get accessor => new VariableAccessor(self);
+  Accessor get accessor => new VariableAccessor(self, null, TreeNode.noOffset);
 
   void extend(VariableDeclaration variable, Expression value) {
     Arguments arguments =
         new Arguments(<Expression>[new IntLiteral(variables.length), value]);
     converter.rewriter.insertExtendContext(expression, arguments);
     ++size.value;
     variables.add(variable);
     initializers[variable] = arguments;
   }
 
@@ skipping 87 matching lines @@
       }
       context = new PropertyGet(context, new Name('parent'));
     }
     throw 'Unbound NestedContext.lookup($variable)';
   }
 
   Context toNestedContext([Accessor accessor]) {
     return new NestedContext(converter, accessor ?? this.accessor, variabless);
   }
 }