Add local type inference logic for integer literals.

pkg/front_end/testcases/inference/int_upwards_local.dart

Index: pkg/front_end/testcases/inference/int_upwards_local.dart
diff --git a/pkg/front_end/testcases/inference/int_upwards_local.dart b/pkg/front_end/testcases/inference/int_upwards_local.dart
new file mode 100644
index 0000000000000000000000000000000000000000..9319ecd48713000e3df398ac713051d74a6b658c
--- /dev/null
+++ b/pkg/front_end/testcases/inference/int_upwards_local.dart
@@ -0,0 +1,8 @@
+// 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*/

[ahe, 2017/04/20 09:45:29]

You should also be able to write this as:

/*@ testedFeatures = inference */

[Paul Berry, 2017/04/20 09:52:57]

Acknowledged.

+main() {
+  var /*@type=dart.core::int*/ x = 1;
+}