[Atomics] Make Atomics.exchange a builtin using TF

src/js/harmony-atomics.js

 // Copyright 2015 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.
 
 (function(global, utils) {
 
 "use strict";
 
 %CheckIsBootstrapping();
 
@@ skipping 75 matching lines @@
   return %_AtomicsOr(ia, index, value);
 }
 
 function AtomicsXorJS(ia, index, value) {
   CheckSharedIntegerTypedArray(ia);
   index = ValidateIndex(index, %_TypedArrayGetLength(ia));
   value = TO_NUMBER(value);
   return %_AtomicsXor(ia, index, value);
 }
 
-function AtomicsExchangeJS(ia, index, value) {
-  CheckSharedIntegerTypedArray(ia);
-  index = ValidateIndex(index, %_TypedArrayGetLength(ia));
-  value = TO_NUMBER(value);
-  return %_AtomicsExchange(ia, index, value);
-}
-
 function AtomicsIsLockFreeJS(size) {
   return %_AtomicsIsLockFree(size);
 }
 
 function AtomicsWaitJS(ia, index, value, timeout) {
   CheckSharedInteger32TypedArray(ia);
   index = ValidateIndex(index, %_TypedArrayGetLength(ia));
   if (IS_UNDEFINED(timeout)) {
     timeout = INFINITY;
   } else {
@@ skipping 24 matching lines @@
 
 utils.InstallFunctions(Atomics, DONT_ENUM, [
   // TODO(binji): remove the rest of the (non futex) Atomics functions as they
   // become builtins.
   "compareExchange", AtomicsCompareExchangeJS,
   "add", AtomicsAddJS,
   "sub", AtomicsSubJS,
   "and", AtomicsAndJS,
   "or", AtomicsOrJS,
   "xor", AtomicsXorJS,
-  "exchange", AtomicsExchangeJS,
   "isLockFree", AtomicsIsLockFreeJS,
   "wait", AtomicsWaitJS,
   "wake", AtomicsWakeJS,
 ]);
 
 })