Remove all harmony runtime flags which shipped in M51

src/js/arraybuffer.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
 
 var GlobalArrayBuffer = global.ArrayBuffer;
 var MakeTypeError;
 var MaxSimple;
 var MinSimple;
 var SpeciesConstructor;
+var speciesSymbol = utils.ImportNow("species_symbol");
 
 utils.Import(function(from) {
   MakeTypeError = from.MakeTypeError;
   MaxSimple = from.MaxSimple;
   MinSimple = from.MinSimple;
   SpeciesConstructor = from.SpeciesConstructor;
 });
 
 // -------------------------------------------------------------------
 
@@ skipping 48 matching lines @@
     throw MakeTypeError(kArrayBufferSpeciesThis);
   }
   if (%_ArrayBufferGetByteLength(result) < newLen) {
     throw MakeTypeError(kArrayBufferTooShort);
   }
 
   %ArrayBufferSliceImpl(this, result, first, newLen);
   return result;
 }
 
+
+function ArrayBufferSpecies() {
+  return this;
+}
+
+utils.InstallGetter(GlobalArrayBuffer, speciesSymbol, ArrayBufferSpecies);
+
 utils.InstallGetter(GlobalArrayBuffer.prototype, "byteLength",
                     ArrayBufferGetByteLen);
 
 utils.InstallFunctions(GlobalArrayBuffer.prototype, DONT_ENUM, [
   "slice", ArrayBufferSlice
 ]);
 
 })