dart2js cps: Change interceptor pipeline.

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

Index: pkg/compiler/lib/src/cps_ir/type_propagation.dart
diff --git a/pkg/compiler/lib/src/cps_ir/type_propagation.dart b/pkg/compiler/lib/src/cps_ir/type_propagation.dart
index 1ac163ee538b0732f31819e3dfb1f7c485a61acb..d894a90c5bc9ae2c97716dfcf29436972550ef2f 100644
--- a/pkg/compiler/lib/src/cps_ir/type_propagation.dart
+++ b/pkg/compiler/lib/src/cps_ir/type_propagation.dart
@@ -2080,16 +2080,9 @@ class TransformingVisitor extends LeafVisitor {
     } else {
       singleClass = typeSystem.singleClass(value.type);
     }
-    if (singleClass != null) {
-      if (singleClass.isSubclassOf(backend.jsInterceptorClass)) {
-        Primitive constant = makeConstantPrimitive(
-            new InterceptorConstantValue(singleClass.rawType));
-        constant.hint = node.hint;
-        return constant;
-      } else {
-        node.input.definition.substituteFor(node);
-        return null;
-      }
+    if (singleClass != null &&
+        singleClass.isSubclassOf(backend.jsInterceptorClass)) {
+      node.constantValue = new InterceptorConstantValue(singleClass.rawType);
     }
     // Filter out intercepted classes that do not match the input type.
     node.interceptedClasses.retainWhere((ClassElement clazz) {