Add type inference of annotations.

pkg/front_end/testcases/inference/downwards_inference_annotations.dart.strong.expect

Index: pkg/front_end/testcases/inference/downwards_inference_annotations.dart.strong.expect
diff --git a/pkg/front_end/testcases/inference/downwards_inference_annotations.dart.strong.expect b/pkg/front_end/testcases/inference/downwards_inference_annotations.dart.strong.expect
new file mode 100644
index 0000000000000000000000000000000000000000..540ec7b3f2ea0dd463d68f92f218dea46b2a80cc
--- /dev/null
+++ b/pkg/front_end/testcases/inference/downwards_inference_annotations.dart.strong.expect
@@ -0,0 +1,25 @@
+library test;
+import self as self;
+import "dart:core" as core;
+
+class Foo extends core::Object {
+  const constructor •(core::List<core::String> l) → void
+    : super core::Object::•()
+    ;
+  const constructor named(core::List<core::String> l) → void
+    : super core::Object::•()
+    ;
+}
+@self::Foo::•(const <core::String>[])
+class Bar extends core::Object {
+  constructor •() → void
+    : super core::Object::•()
+    ;
+}
+@self::Foo::named(const <core::String>[])
+class Baz extends core::Object {
+  constructor •() → void
+    : super core::Object::•()
+    ;
+}
+static method main() → dynamic {}