dart2js cps: Change interceptor pipeline.

pkg/compiler/lib/src/cps_ir/cps_ir_nodes.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_nodes;
 
 import 'dart:collection';
-import '../constants/values.dart' as values show ConstantValue;
+import '../constants/values.dart' as values;
 import '../dart_types.dart' show DartType, InterfaceType, TypeVariableType;
 import '../elements/elements.dart';
 import '../io/source_information.dart' show SourceInformation;
 import '../types/types.dart' show TypeMask;
 import '../universe/universe.dart' show Selector;
 
 import 'builtin_operator.dart';
 export 'builtin_operator.dart';
 
 // These imports are only used for the JavaScript specific nodes.  If we want to
@@ skipping 944 matching lines @@
   bool get isSafeForReordering => true;
 
   toString() => 'CreateInstance($classElement)';
 }
 
 class Interceptor extends Primitive {
   final Reference<Primitive> input;
   final Set<ClassElement> interceptedClasses = new Set<ClassElement>();
   final SourceInformation sourceInformation;
 
+  /// If non-null, all uses of this the interceptor call are guaranteed to
+  /// see this value.
+  ///
+  /// The interceptor call is not immediately replaced by the constant, because
+  /// that might prevent the interceptor from being shared.
+  ///
+  /// The precise input type is not known when sharing interceptors, because
+  /// refinement nodes have been removed by then. So this field carries the
+  /// known constant until we know if it should be shared or replaced by
+  /// the constant.
+  values.InterceptorConstantValue constantValue;
+
   Interceptor(Primitive input, this.sourceInformation)
       : this.input = new Reference<Primitive>(input);
 
   accept(Visitor visitor) => visitor.visitInterceptor(this);
 
   bool get isSafeForElimination => true;
   bool get isSafeForReordering => true;
 }
 
 /// Create an instance of [Invocation] for use in a call to `noSuchMethod`.
@@ skipping 739 matching lines @@
 /// Visit a just-deleted subterm and unlink all [Reference]s in it.
 class RemovalVisitor extends RecursiveVisitor {
   processReference(Reference reference) {
     reference.unlink();
   }
 
   static void remove(Node node) {
     (new RemovalVisitor()).visit(node);
   }
 }