[intrinsics] Kill the %_IsMinusZero intrinsic.

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 19 matching lines @@
 function add(x, y) {
   return x + y;
 }
 
 assertEquals(0, add(0, 0));
 assertEquals(0, add(0, 0));
 %OptimizeFunctionOnNextCall(add);
 assertEquals(-0, add(-0, -0));
 
 
-function test(x, y) {
-  assertTrue(%_IsMinusZero(-0));
-  assertTrue(%_IsMinusZero(1/(-Infinity)));
-  assertTrue(%_IsMinusZero(x));
-
-  assertFalse(%_IsMinusZero(0));
-  assertFalse(%_IsMinusZero(1/Infinity));
-  assertFalse(%_IsMinusZero(0.1));
-  assertFalse(%_IsMinusZero(-0.2));
-  assertFalse(%_IsMinusZero({}));
-  assertFalse(%_IsMinusZero(""));
-  assertFalse(%_IsMinusZero("-0"));
-  assertFalse(%_IsMinusZero(function() {}));
-  assertFalse(%_IsMinusZero(y));
-}
-
-test(-0, 1.2);
-test(-0, 1.2);
-%OptimizeFunctionOnNextCall(test);
-test(-0, 1.2);
-assertOptimized(test);
-
-
 function testsin() {
-  assertTrue(%_IsMinusZero(Math.sin(-0)));
+  assertEquals(-0, Math.sin(-0));
 }
 
 testsin();
 testsin();
 %OptimizeFunctionOnNextCall(testsin);
 testsin();
 
 
 function testfloor() {
-  assertTrue(%_IsMinusZero(Math.floor(-0)));
-  assertFalse(%_IsMinusZero(Math.floor(2)));
+  assertEquals(-0, Math.floor(-0));
 }
 
 testfloor();
 testfloor();
 %OptimizeFunctionOnNextCall(testfloor);
 testfloor();
 
 
 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));