Handle deferred access as pre-step in SemanticSendVisitor.

pkg/compiler/lib/src/cps_ir/cps_ir_builder_task.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_task;
 
 import '../closure.dart' as closurelib;
 import '../closure.dart' hide ClosureScope;
 import '../constants/expressions.dart';
 import '../dart_types.dart';
@@ skipping 594 matching lines @@
       return giveup(node, 'assert in checked mode not implemented');
     } else {
       // The call to assert and its argument expression must be ignored
       // in production mode.
       // Assertions can onl)y occur in expression statements, so no value needs
       // to be returned.
       return null;
     }
   }
 
+  @override
+  void previsitDeferredAccess(ast.Send node, PrefixElement prefix, _) {
+    giveup(node, 'deferred access is not implemented');
+  }
+
   ir.Primitive visitNamedArgument(ast.NamedArgument node) {
     assert(irBuilder.isOpen);
     return visit(node.expression);
   }
 
   @override
   ir.Primitive visitExpressionInvoke(ast.Send node,
                                      ast.Node expression,
                                      ast.NodeList argumentsNode,
                                      Selector selector, _) {
@@ skipping 2778 matching lines @@
   }
 
   processSetStatic(ir.SetStatic node) {
     node.body = replacementFor(node.body);
   }
 
   processContinuation(ir.Continuation node) {
     node.body = replacementFor(node.body);
   }
 }