Fix constructor invocation type inference.

pkg/front_end/testcases/inference/instance_creation_downwards.dart

Index: pkg/front_end/testcases/inference/instance_creation_downwards.dart
diff --git a/pkg/front_end/testcases/inference/instance_creation_downwards.dart b/pkg/front_end/testcases/inference/instance_creation_downwards.dart
new file mode 100644
index 0000000000000000000000000000000000000000..f0669481a2002f6f5bd21a821d9bfb26f34b790f
--- /dev/null
+++ b/pkg/front_end/testcases/inference/instance_creation_downwards.dart
@@ -0,0 +1,17 @@
+// Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+/*@testedFeatures=inference*/
+library test;
+
+class A<T> {
+  A(B<List<T>> b);
+}
+
+class B<T> {}
+
+main() {
+  var /*@type=A<dynamic>*/ x =
+      new /*@typeArgs=dynamic*/ A(new /*@typeArgs=List<dynamic>*/ B());
+}