Infer types of bool/null/string literals.

pkg/front_end/testcases/inference/simple_literal_bool.dart

Index: pkg/front_end/testcases/inference/simple_literal_bool.dart
diff --git a/pkg/front_end/testcases/inference/simple_literal_bool.dart b/pkg/front_end/testcases/inference/simple_literal_bool.dart
new file mode 100644
index 0000000000000000000000000000000000000000..265b08b7cb2eb33dd943a88c005715c2e96c8ec2
--- /dev/null
+++ b/pkg/front_end/testcases/inference/simple_literal_bool.dart
@@ -0,0 +1,12 @@
+// 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.md file.
+
+/*@testedFeatures=inference*/
+library test;
+
+var /*@topType=bool*/ a = true;
+
+main() {
+  var /*@type=bool*/ b = false;
+}