Tweak minus zero detect of HChange

test/mjsunit/compiler/minus-zero.js

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 73 matching lines @@
 var double_one = Math.cos(0);
 
 function add(a, b) {
   return a + b;
 }
 
 assertEquals(1, 1/add(double_one, 0));
 assertEquals(1, 1/add(0, double_one));
 %OptimizeFunctionOnNextCall(add);
 assertEquals(1/(-0 + -0), 1/add(-0, -0));
+
+
+function foo(x, y, z) {
+  var w = x * y;
+  return w + z;
+}
+
+assertEquals(1, foo(0, 1, 1));
+assertEquals(1, foo(0, 1, 1));
+%OptimizeFunctionOnNextCall(foo);
+assertEquals(1, foo(0, -1, 1));
+assertOptimized(foo);