Handle deferred access as pre-step in SemanticSendVisitor.

pkg/compiler/lib/src/inferrer/inferrer_visitor.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 inferrer_visitor;
 
 import '../constants/constant_system.dart';
 import '../constants/expressions.dart';
 import '../dart2jslib.dart' hide Selector, TypedSelector;
 import '../dart_types.dart';
@@ skipping 798 matching lines @@
     // symbol is always a non-null exact symbol implementation -- not just
     // any non-null subtype of the symbol interface.
     return types.nonNullSubtype(compiler.symbolClass);
   }
 
   T visitTypePrefixSend(Send node) {
     // TODO(johnniwinther): Remove the need for handling this node.
     return types.dynamicType;
   }
 
+  @override
+  void previsitDeferredAccess(Send node, PrefixElement prefix, _) {
+    // Deferred access does not affect inference.
+  }
+
   T handleTypeLiteralGet() {
     return types.typeType;
   }
 
   T handleTypeLiteralInvoke(NodeList arguments) {
     return types.dynamicType;
   }
 
   T visitClassTypeLiteralGet(
       Send node,
@@ skipping 614 matching lines @@
     return type;
   }
 
   T visitCascade(Cascade node) {
     // Ignore the result of the cascade send and return the type of the cascade
     // receiver.
     visit(node.expression);
     return cascadeReceiverStack.removeLast();
   }
 }