cps-ir: Clean-ups in type propagator.

tests/compiler/dart2js/js_backend_cps_ir_control_flow_test.dart

Index: tests/compiler/dart2js/js_backend_cps_ir_control_flow_test.dart
diff --git a/tests/compiler/dart2js/js_backend_cps_ir_control_flow_test.dart b/tests/compiler/dart2js/js_backend_cps_ir_control_flow_test.dart
index e35e90f99898e040c8efe957de6daba83551e398..1b999bcc091685c2541d026b632d980c5d7dd370 100644
--- a/tests/compiler/dart2js/js_backend_cps_ir_control_flow_test.dart
+++ b/tests/compiler/dart2js/js_backend_cps_ir_control_flow_test.dart
@@ -133,8 +133,7 @@ main() {
   }
 }""","""
 function() {
-  V.foo();
-  P.print("good");
+  P.identical(V.foo(), true) ? P.print("bad") : P.print("good");
   return null;
 }"""),
 ];