Get rid of promotedType=none annotations

pkg/front_end/testcases/inference/future_then_upwards.dart

Index: pkg/front_end/testcases/inference/future_then_upwards.dart
diff --git a/pkg/front_end/testcases/inference/future_then_upwards.dart b/pkg/front_end/testcases/inference/future_then_upwards.dart
index d62ce4ce0f03ed342038f105ad0fd8db63196185..7508eef606e9412d760858e72371c0a7ff7f0d12 100644
--- a/pkg/front_end/testcases/inference/future_then_upwards.dart
+++ b/pkg/front_end/testcases/inference/future_then_upwards.dart
@@ -18,7 +18,7 @@ void main() {
   var /*@type=MyFuture<double>*/ f =
       foo(). /*@typeArgs=double*/ /*@target=MyFuture::then*/ then(
           /*@returnType=double*/ (/*@type=dynamic*/ _) => 2.3);
-  Future<int> f2 = /*error:INVALID_ASSIGNMENT*/ /*@promotedType=none*/ f;
+  Future<int> f2 = /*error:INVALID_ASSIGNMENT*/ f;
 
   // The unnecessary cast is to illustrate that we inferred <double> for
   // the generic type args, even though we had a return type context.