dart2js cps: Compute intercepted classes in optimize_interceptors.

pkg/compiler/lib/src/cps_ir/gvn.dart

 // Copyright (c) 2015, 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.cps_ir.gvn;
 
 import 'cps_ir_nodes.dart';
 import '../universe/side_effects.dart';
 import '../elements/elements.dart';
 import 'optimizers.dart' show Pass;
@@ skipping 141 matching lines @@
     gvnFor[prim] = gvn;
 
     // Try to reuse a previously computed value with the same GVN.
     Primitive existing = environment[gvn];
     if (existing != null &&
         canReplaceWithExistingValue(prim) &&
         !isTrivialPrimitive(prim)) {
       if (prim is Interceptor) {
         Interceptor interceptor = existing;
         interceptor.interceptedClasses.addAll(prim.interceptedClasses);
-        interceptor.flags |= prim.flags;
       }
       prim..replaceUsesWith(existing)..destroy();
       node.remove();
       return next;
     }
 
     if (tryToHoistOutOfLoop(prim, gvn)) {
       return next;
     }
 
@@ skipping 570 matching lines @@
 
   @override
   processReference(Reference ref) {
     callback(ref);
   }
 
   static void forEach(Primitive node, ReferenceCallback callback) {
     new InputVisitor(callback).visit(node);
   }
 }