dart2js cps: Set receiver type in type propagation.

pkg/compiler/lib/src/js_backend/codegen/codegen.dart

 // Copyright (c) 2014, 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 code_generator;
 
 import 'glue.dart';
 
 import '../../tree_ir/tree_ir_nodes.dart' as tree_ir;
 import '../../tree_ir/tree_ir_nodes.dart' show BuiltinOperator;
@@ skipping 617 matching lines @@
     glue.registerUseInterceptorInCodegen();
     registry.registerSpecializedGetInterceptor(node.interceptedClasses);
     js.Name helperName = glue.getInterceptorName(node.interceptedClasses);
     js.Expression globalHolder = glue.getInterceptorLibrary();
     return js.js('#.#(#)',
         [globalHolder, helperName, visitExpression(node.input)]);
   }
 
   @override
   js.Expression visitGetField(tree_ir.GetField node) {
+    registry.registerFieldGetter(node.field);
     return new js.PropertyAccess(
         visitExpression(node.object),
         glue.instanceFieldPropertyName(node.field));
   }
 
   @override
   js.Assignment visitSetField(tree_ir.SetField node) {
+    registry.registerFieldSetter(node.field);
     js.PropertyAccess field =
         new js.PropertyAccess(
             visitExpression(node.object),
             glue.instanceFieldPropertyName(node.field));
     return new js.Assignment(field, visitExpression(node.value));
   }
 
   @override
   js.Expression visitGetStatic(tree_ir.GetStatic node) {
     assert(node.element is FieldElement || node.element is FunctionElement);
@@ skipping 126 matching lines @@
         return js.js("typeof # === 'number' && Math.floor(#) === #", args);
     }
   }
 
   visitFunctionExpression(tree_ir.FunctionExpression node) {
     // FunctionExpressions are currently unused.
     // We might need them if we want to emit raw JS nested functions.
     throw 'FunctionExpressions should not be used';
   }
 }