[intrinsics] Kill the %_IsMinusZero intrinsic.

src/js/runtime.js

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This files contains runtime support implemented in JavaScript.
 
 // CAUTION: Some of the functions specified in this file are called
 // directly from compiled code. These are the functions with names in
 // ALL CAPS. The compiled code passes the first argument in 'this'.
 
@@ skipping 25 matching lines @@
 
 // ----------------------------------------------------------------------------
 
 /* -------------------------------------
    - - -   C o n v e r s i o n s   - - -
    -------------------------------------
 */
 
 // ES5, section 9.12
 function SameValue(x, y) {
-  if (typeof x != typeof y) return false;
+  if (typeof x !== typeof y) return false;
   if (IS_NUMBER(x)) {
     if (NUMBER_IS_NAN(x) && NUMBER_IS_NAN(y)) return true;
     // x is +0 and y is -0 or vice versa.
-    if (x === 0 && y === 0 && %_IsMinusZero(x) != %_IsMinusZero(y)) {
+    if (x === 0 && y === 0 && 1/x !== 1/y) {
       return false;
     }
   }
   if (IS_SIMD_VALUE(x)) return %SimdSameValue(x, y);
   return x === y;
 }
 
 
 // ES6, section 7.2.4
 function SameValueZero(x, y) {
-  if (typeof x != typeof y) return false;
+  if (typeof x !== typeof y) return false;
   if (IS_NUMBER(x)) {
     if (NUMBER_IS_NAN(x) && NUMBER_IS_NAN(y)) return true;
   }
   if (IS_SIMD_VALUE(x)) return %SimdSameValueZero(x, y);
   return x === y;
 }
 
 
 function ConcatIterableToArray(target, iterable) {
    var index = target.length;
@@ skipping 96 matching lines @@
   to.SameValueZero = SameValueZero;
   to.ToPositiveInteger = ToPositiveInteger;
   to.SpeciesConstructor = SpeciesConstructor;
 });
 
 %InstallToContext([
   "concat_iterable_to_array", ConcatIterableToArray,
 ]);
 
 })