Lift nearly all top-level type inference restrictions.

pkg/front_end/testcases/inference/infer_assign_to_index.dart

Index: pkg/front_end/testcases/inference/infer_assign_to_index.dart
diff --git a/pkg/front_end/testcases/inference/infer_assign_to_index.dart b/pkg/front_end/testcases/inference/infer_assign_to_index.dart
deleted file mode 100644
index 7ea82f707959da20b40add95a8bf79f5ddf65b68..0000000000000000000000000000000000000000
--- a/pkg/front_end/testcases/inference/infer_assign_to_index.dart
+++ /dev/null
@@ -1,12 +0,0 @@
-// 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;
-
-List<double> a = <double>[];
-var /*@topType=dynamic*/ b =
-    (/*error:TOP_LEVEL_UNSUPPORTED*/ a /*@target=List::[]=*/ [0] = 1.0);
-
-main() {}