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

tests/language_strong/lazy_static3_test.dart

 // Copyright (c) 2012, 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";
 
 final x = foo();
 var x2 = foo2();
 var x3 = foo3();
 var x4 = foo4();
 var x5 = foo5();
 final x6 = foo6();
-var x7 = x7 + 1;
+int x7 = x7 + 1;
 
 foo() { throw "interrupt initialization"; }
 foo2() { x2 = 499; throw "interrupt initialization"; }
 foo3() => x3 + 1;
 foo4() {
   x4 = 498;
   x4 = x4 + 1;
   return x4;
 }
 foo5() {
@@ skipping 25 matching lines @@
   Expect.equals(null, x3);
 
   Expect.equals(499, x4);
 
   Expect.equals(null, x5);
 
   Expect.equals(499, x6);
 
   Expect.throws(() => fib(x7), (e) => e is CyclicInitializationError);
 }