dart2js: Add a type parameter to class Reference in the CPS IR.

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

Index: pkg/compiler/lib/src/cps_ir/constant_propagation.dart
diff --git a/pkg/compiler/lib/src/cps_ir/constant_propagation.dart b/pkg/compiler/lib/src/cps_ir/constant_propagation.dart
index 985cd279b8153b3c396327869f3f6a48c1013c5b..fc9ebba0fed2f353a69aade7efe5ce42d1bc860f 100644
--- a/pkg/compiler/lib/src/cps_ir/constant_propagation.dart
+++ b/pkg/compiler/lib/src/cps_ir/constant_propagation.dart
@@ -83,7 +83,7 @@ class _TransformingVisitor extends RecursiveVisitor {
     Constant constant = new Constant(constExp);
     LetPrim letPrim = new LetPrim(constant);
     InvokeContinuation invoke =
-        new InvokeContinuation(continuation, <Definition>[constant]);
+        new InvokeContinuation(continuation, <Primitive>[constant]);
 
     invoke.parent = constant.parent = letPrim;
     letPrim.body = invoke;
@@ -124,7 +124,7 @@ class _TransformingVisitor extends RecursiveVisitor {
 
     assert(successor.parameters.isEmpty);
     InvokeContinuation invoke =
-        new InvokeContinuation(successor, <Definition>[]);
+        new InvokeContinuation(successor, <Primitive>[]);
 
     InteriorNode parent = node.parent;
     invoke.parent = parent;