Fix top-level inference errors for most of the newly failing tests.

tests/language_strong/lazy_static7_test.dart

 // Copyright (c) 2015, 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.
 
 import "package:expect/expect.dart";
 
 var sideEffect = 0;
-var x = (() { sideEffect++; return 499; })();
+int x = (() { sideEffect++; return 499; })();
 
 main() {
   if (new DateTime.now().day >= -1) {
     x = 42;
   }
   Expect.equals(42, x);
   Expect.equals(0, sideEffect);
 }