dart2js cps: Store the TypeMask for each primitive in a field.

pkg/compiler/lib/src/cps_ir/insert_refinements.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 cps_ir.optimization.insert_refinements;
 
 import 'optimizers.dart' show Pass;
 import 'shrinking_reductions.dart' show ParentVisitor;
 import 'cps_ir_nodes.dart';
 import '../types/constants.dart';
@@ skipping 145 matching lines @@
     Continuation falseCont = node.falseContinuation.definition;
 
     // Sink both continuations to the Branch to ensure everything in scope
     // here is also in scope inside the continuations.
     sinkContinuationToUse(trueCont, node);
     sinkContinuationToUse(falseCont, node);
 
     // If the condition is an 'is' check, promote the checked value.
     if (condition is TypeTest) {
       Primitive value = condition.value.definition;
-      TypeMask type = types.subtypesOf(condition.type);
+      TypeMask type = types.subtypesOf(condition.dartType);
       Primitive refinedValue = new Refinement(value, type);
       pushRefinement(trueCont, refinedValue);
       push(falseCont);
       return;
     }
 
     // If the condition is comparison with a constant, promote the other value.
     // This can happen either for calls to `==` or `identical` calls, such
     // as the ones inserted by the unsugaring pass.
 
@@ skipping 46 matching lines @@
            cont.firstRef.parent is Branch)) {
         // Do not push the continuation here.
         // visitInvokeMethod and visitBranch will do that.
       } else {
         push(cont);
       }
     }
     return node.body;
   }
 }