Fixes obo error in javascript int checking.

tests/standalone/javascript_int_overflow_test.dart

 // Copyright (c) 2013, 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.
 
 // VMOptions=--throw_on_javascript_int_overflow --optimization_counter_threshold=10
 
 
 import "package:expect/expect.dart";
 import 'dart:typed_data';
 
@@ skipping 11 matching lines @@
 }
 
 
 int is_arg;
 int integer_shift() {
   return is_arg << 1;
 }
 
 
 int max_add_throws() {
-  return 0x1FFFFFFFFFFFFF + 1;
+  return 0x20000000000000 + 1;
 }
 
 
 int min_sub_throws() {
-  return -0x1FFFFFFFFFFFFF - 1;
+  return -0x20000000000000 - 1;
 }
 
 
 int n_arg;
 int negate() {
   return -n_arg;
 }
 
 
 int max_literal() {
-  return 0x1FFFFFFFFFFFFF;
+  return 0x20000000000000;
 }
 
 
 int min_literal() {
-  var min_literal = -0x1FFFFFFFFFFFFF;
+  var min_literal = -0x20000000000000;
   return min_literal;
 }
 
 // We don't test for the _JavascriptIntegerOverflowError since it's not visible.
 // It should not be visible since it doesn't exist on dart2js.
 bool isJavascriptIntError(e) =>
     e is Error && "$e".startsWith("Javascript Integer Overflow:");
 
 main() {
-  Expect.equals(0x1FFFFFFFFFFFFF, max_literal());
-  Expect.equals(-0x1FFFFFFFFFFFFF, min_literal());
+  Expect.equals(0x20000000000000, max_literal());
+  Expect.equals(-0x20000000000000, min_literal());
 
   // Run the tests once before optimizations.
-  dti_arg = 1.9e16;
+  dti_arg = 1.9e17;
   Expect.throws(double_to_int, isJavascriptIntError);
 
-  ia_arg1 = (1 << 52);
-  ia_arg2 = (1 << 52);
+  ia_arg1 = (1 << 53);
+  ia_arg2 = (1 << 53);
   Expect.throws(integer_add, isJavascriptIntError);
 
-  n_arg = -0x1FFFFFFFFFFFFF;
-  Expect.equals(0x1FFFFFFFFFFFFF, negate());
+  n_arg = -0x20000000000000;
+  Expect.equals(0x20000000000000, negate());
 
-  is_arg = (1 << 52);
+  is_arg = (1 << 53);
   Expect.throws(integer_shift, isJavascriptIntError);
 
   Expect.throws(max_add_throws, isJavascriptIntError);
   Expect.throws(min_sub_throws, isJavascriptIntError);
 
   for (int i = 0; i < 20; i++) {
     dti_arg = i.toDouble();
     // Expect.throws calls through the closure, so we have to here, too.
     var f = double_to_int;
     Expect.equals(i, f());
 
     ia_arg1 = i;
     ia_arg2 = i;
     f = integer_add;
     Expect.equals(i + i, f());
 
     n_arg = i;
     f = negate;
     Expect.equals(-i, f());
 
     is_arg = i;
     f = integer_shift;
     Expect.equals(i << 1, f());
   }
 
    // The optimized functions should now deoptimize and throw the error.
-  dti_arg = 1.9e16;
+  dti_arg = 1.9e17;
   Expect.throws(double_to_int, isJavascriptIntError);
 
-  ia_arg1 = (1 << 52);
-  ia_arg2 = (1 << 52);
+  ia_arg1 = (1 << 53);
+  ia_arg2 = (1 << 53);
   Expect.throws(integer_add, isJavascriptIntError);
 
-  n_arg = -0x1FFFFFFFFFFFFF;
-  Expect.equals(0x1FFFFFFFFFFFFF, negate());
+  n_arg = -0x20000000000000;
+  Expect.equals(0x20000000000000, negate());
 
-  is_arg = (1 << 52);
+  is_arg = (1 << 53);
   Expect.throws(integer_shift, isJavascriptIntError);
 
   Expect.throws(max_add_throws, isJavascriptIntError);
   Expect.throws(min_sub_throws, isJavascriptIntError);
 }