Revert of [typedarrays] move %TypedArray%.prototype.copyWithin to C++

src/js/typedarray.js

 // Copyright 2013 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();
 
 // -------------------------------------------------------------------
 // Imports
 
 // array.js has to come before typedarray.js for this to work
 var ArrayToString = utils.ImportNow("ArrayToString");
 var ArrayValues;
 var GetIterator;
 var GetMethod;
 var GlobalArray = global.Array;
 var GlobalArrayBuffer = global.ArrayBuffer;
 var GlobalArrayBufferPrototype = GlobalArrayBuffer.prototype;
 var GlobalObject = global.Object;
+var InnerArrayCopyWithin;
 var InnerArrayEvery;
 var InnerArrayFill;
 var InnerArrayFilter;
 var InnerArrayFind;
 var InnerArrayFindIndex;
 var InnerArrayForEach;
 var InnerArrayJoin;
 var InnerArrayReduce;
 var InnerArrayReduceRight;
 var InnerArraySome;
@@ skipping 27 matching lines @@
 endmacro
 
 TYPED_ARRAYS(DECLARE_GLOBALS)
 
 var GlobalTypedArray = %object_get_prototype_of(GlobalUint8Array);
 
 utils.Import(function(from) {
   ArrayValues = from.ArrayValues;
   GetIterator = from.GetIterator;
   GetMethod = from.GetMethod;
+  InnerArrayCopyWithin = from.InnerArrayCopyWithin;
   InnerArrayEvery = from.InnerArrayEvery;
   InnerArrayFill = from.InnerArrayFill;
   InnerArrayFilter = from.InnerArrayFilter;
   InnerArrayFind = from.InnerArrayFind;
   InnerArrayFindIndex = from.InnerArrayFindIndex;
   InnerArrayForEach = from.InnerArrayForEach;
   InnerArrayJoin = from.InnerArrayJoin;
   InnerArrayReduce = from.InnerArrayReduce;
   InnerArrayReduceRight = from.InnerArrayReduceRight;
   InnerArraySome = from.InnerArraySome;
@@ skipping 349 matching lines @@
 %FunctionSetLength(TypedArraySet, 1);
 
 function TypedArrayGetToStringTag() {
   if (!IS_TYPEDARRAY(this)) return;
   var name = %_ClassOf(this);
   if (IS_UNDEFINED(name)) return;
   return name;
 }
 
 
+function TypedArrayCopyWithin(target, start, end) {
+  if (!IS_TYPEDARRAY(this)) throw %make_type_error(kNotTypedArray);
+
+  var length = %_TypedArrayGetLength(this);
+
+  // TODO(littledan): Replace with a memcpy for better performance
+  return InnerArrayCopyWithin(target, start, end, this, length);
+}
+%FunctionSetLength(TypedArrayCopyWithin, 2);
+
+
 // ES6 draft 05-05-15, section 22.2.3.7
 function TypedArrayEvery(f, receiver) {
   if (!IS_TYPEDARRAY(this)) throw %make_type_error(kNotTypedArray);
 
   var length = %_TypedArrayGetLength(this);
 
   return InnerArrayEvery(f, receiver, this, length);
 }
 %FunctionSetLength(TypedArrayEvery, 1);
 
@@ skipping 389 matching lines @@
 %SetCode(GlobalTypedArray, TypedArrayConstructor);
 utils.InstallFunctions(GlobalTypedArray, DONT_ENUM, [
   "from", TypedArrayFrom,
   "of", TypedArrayOf
 ]);
 utils.InstallGetter(GlobalTypedArray.prototype, toStringTagSymbol,
                     TypedArrayGetToStringTag);
 utils.InstallFunctions(GlobalTypedArray.prototype, DONT_ENUM, [
   "subarray", TypedArraySubArray,
   "set", TypedArraySet,
+  "copyWithin", TypedArrayCopyWithin,
   "every", TypedArrayEvery,
   "fill", TypedArrayFill,
   "filter", TypedArrayFilter,
   "find", TypedArrayFind,
   "findIndex", TypedArrayFindIndex,
   "includes", TypedArrayIncludes,
   "indexOf", TypedArrayIndexOf,
   "join", TypedArrayJoin,
   "lastIndexOf", TypedArrayLastIndexOf,
   "forEach", TypedArrayForEach,
@@ skipping 23 matching lines @@
   %AddNamedProperty(GlobalNAME.prototype,
                     "constructor", global.NAME, DONT_ENUM);
   %AddNamedProperty(GlobalNAME.prototype,
                     "BYTES_PER_ELEMENT", ELEMENT_SIZE,
                     READ_ONLY | DONT_ENUM | DONT_DELETE);
 endmacro
 
 TYPED_ARRAYS(SETUP_TYPED_ARRAY)
 
 })