Fix test by correcting the smi range (assuming one tag bit and one sign bit).

tests/compiler/dart2js_extra/hash_code_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";
 
 // dart2js specific test to make sure hashCode on intercepted types behaves as
 // intended.
 
 
 class Hasher {
   confuse(x) => [1, 'x', true, null, x].last;
   hash(x) => confuse(x).hashCode;
 }
 
 // Hashing via [hash] should be forced to use the general interceptor, but the
 // local x.hashCode calls might be optimized.
 var hash = new Hasher().hash;
 
 check(value1, value2) {
   var h1 = hash(value1);
   var h2 = hash(value2);
 
   Expect.isTrue(h1 is int);
   Expect.isTrue(h2 is int);
   Expect.isFalse(h1 == h2);
 
   // We expect that the hash function is reasonable quality - there are some
   // difference in the low bits.
   Expect.isFalse((h1 & 0xf) == (h2 & 0xf));

[ahe, 2013/06/04 06:02:46]

I think this test is flaky.

 
   // Quality check - the values should be SMIs for efficient arithmetic.
-  Expect.equals((h1 & 0x1fffffff), h1);
-  Expect.equals((h2 & 0x1fffffff), h2);
+  Expect.equals((h1 & 0x3fffffff), h1);
+  Expect.equals((h2 & 0x3fffffff), h2);
 }
 
 bools() {
   check(true, false);
 
   Expect.equals(true.hashCode, hash(true));   // First can be optimized.
   Expect.equals(false.hashCode, hash(false));
 }
 
 ints() {
@@ skipping 29 matching lines @@
   Expect.equals(0x0DB819B, 'b'.hashCode);
   Expect.equals(0xEBA5D59, 'c'.hashCode);
 }
 
 main() {
   bools();
   ints();
   lists();
   strings();
 }