Add type inference of annotations.

pkg/front_end/testcases/inference/downwards_inference_annotations_parameter.dart

Index: pkg/front_end/testcases/inference/downwards_inference_annotations_parameter.dart
diff --git a/pkg/front_end/testcases/inference/downwards_inference_annotations.dart b/pkg/front_end/testcases/inference/downwards_inference_annotations_parameter.dart
similarity index 68%
copy from pkg/front_end/testcases/inference/downwards_inference_annotations.dart
copy to pkg/front_end/testcases/inference/downwards_inference_annotations_parameter.dart
index fd31916c8fdba60cc4e6fb865ba35525d4a952b5..e4a9deaa0c87c7c582092a0c2acb44b923519e6d 100644
--- a/pkg/front_end/testcases/inference/downwards_inference_annotations.dart
+++ b/pkg/front_end/testcases/inference/downwards_inference_annotations_parameter.dart
@@ -7,11 +7,12 @@ library test;
 
 class Foo {
   const Foo(List<String> l);
-  const Foo.named(List<String> l);
 }
 
-@Foo(/*@typeArgs=String*/ const [])
-class Bar {}
+void f(@Foo(/*@typeArgs=String*/ const []) x) {}
 
-@Foo.named(/*@typeArgs=String*/ const [])
-class Baz {}
+class C {
+  void m(@Foo(/*@typeArgs=String*/ const []) /*@topType=dynamic*/ x) {}
+}
+
+main() {}