Add type inference of annotations.

pkg/front_end/testcases/inference/downwards_inference_annotations_for_loop_variable.dart

Index: pkg/front_end/testcases/inference/downwards_inference_annotations_for_loop_variable.dart
diff --git a/pkg/front_end/testcases/inference/downwards_inference_annotations.dart b/pkg/front_end/testcases/inference/downwards_inference_annotations_for_loop_variable.dart
similarity index 60%
copy from pkg/front_end/testcases/inference/downwards_inference_annotations.dart
copy to pkg/front_end/testcases/inference/downwards_inference_annotations_for_loop_variable.dart
index fd31916c8fdba60cc4e6fb865ba35525d4a952b5..d92e8a9ec32ccd697c3452f70871e82b67eb3d80 100644
--- a/pkg/front_end/testcases/inference/downwards_inference_annotations.dart
+++ b/pkg/front_end/testcases/inference/downwards_inference_annotations_for_loop_variable.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 test() {
+  for (@Foo(/*@typeArgs=String*/ const []) int i = 0;
+       i /*@target=num::<*/< 1; i++) {}
+  for (@Foo(/*@typeArgs=String*/ const []) int i in /*@typeArgs=int*/[0]) {}
+}
 
-@Foo.named(/*@typeArgs=String*/ const [])
-class Baz {}
+main() {}