Get rid of promotedType=none annotations

pkg/front_end/testcases/inference/null_coalescing_operator.dart

Index: pkg/front_end/testcases/inference/null_coalescing_operator.dart
diff --git a/pkg/front_end/testcases/inference/null_coalescing_operator.dart b/pkg/front_end/testcases/inference/null_coalescing_operator.dart
index 7821f5c4fa04f408af2ecc7ad5d6d4e39776ce49..952477e2f7f18b62c886ddaccaa9cdfe8b671f2a 100644
--- a/pkg/front_end/testcases/inference/null_coalescing_operator.dart
+++ b/pkg/front_end/testcases/inference/null_coalescing_operator.dart
@@ -7,6 +7,6 @@ library test;
 
 main() {
   List<int> x;
-  var /*@type=List<int>*/ y = /*@promotedType=none*/ x ?? /*@typeArgs=int*/ [];
-  List<int> z = /*@promotedType=none*/ y;
+  var /*@type=List<int>*/ y = x ?? /*@typeArgs=int*/ [];
+  List<int> z = y;
 }