Optimize add/set/delete operations for string keys in Maps and Sets

src/collection.js

 // Copyright 2012 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.
 
 "use strict";
 
 // This file relies on the fact that the following declaration has been made
 // in runtime.js:
 // var $Array = global.Array;
 
@@ skipping 38 matching lines @@
     throw MakeTypeError('incompatible_method_receiver',
                         ['Set.prototype.add', this]);
   }
   // Normalize -0 to +0 as required by the spec.
   // Even though we use SameValueZero as the comparison for the keys we don't
   // want to ever store -0 as the key since the key is directly exposed when
   // doing iteration.
   if (key === 0) {
     key = 0;
   }
-  return %SetAdd(this, key);
+  return %_SetAdd(this, key);
 }
 
 
 function SetHasJS(key) {
   if (!IS_SET(this)) {
     throw MakeTypeError('incompatible_method_receiver',
                         ['Set.prototype.has', this]);
   }
   return %_SetHas(this, key);
 }
 
 
 function SetDeleteJS(key) {
   if (!IS_SET(this)) {
     throw MakeTypeError('incompatible_method_receiver',
                         ['Set.prototype.delete', this]);
   }
-  return %SetDelete(this, key);
+  return %_SetDelete(this, key);
 }
 
 
 function SetGetSizeJS() {
   if (!IS_SET(this)) {
     throw MakeTypeError('incompatible_method_receiver',
                         ['Set.prototype.size', this]);
   }
   return %_SetGetSize(this);
 }
@@ skipping 114 matching lines @@
     throw MakeTypeError('incompatible_method_receiver',
                         ['Map.prototype.set', this]);
   }
   // Normalize -0 to +0 as required by the spec.
   // Even though we use SameValueZero as the comparison for the keys we don't
   // want to ever store -0 as the key since the key is directly exposed when
   // doing iteration.
   if (key === 0) {
     key = 0;
   }
-  return %MapSet(this, key, value);
+  return %_MapSet(this, key, value);
 }
 
 
 function MapHasJS(key) {
   if (!IS_MAP(this)) {
     throw MakeTypeError('incompatible_method_receiver',
                         ['Map.prototype.has', this]);
   }
   return %_MapHas(this, key);
 }
 
 
 function MapDeleteJS(key) {
   if (!IS_MAP(this)) {
     throw MakeTypeError('incompatible_method_receiver',
                         ['Map.prototype.delete', this]);
   }
-  return %MapDelete(this, key);
+  return %_MapDelete(this, key);
 }
 
 
 function MapGetSizeJS() {
   if (!IS_MAP(this)) {
     throw MakeTypeError('incompatible_method_receiver',
                         ['Map.prototype.size', this]);
   }
   return %_MapGetSize(this);
 }
@@ skipping 54 matching lines @@
     "get", MapGetJS,
     "set", MapSetJS,
     "has", MapHasJS,
     "delete", MapDeleteJS,
     "clear", MapClearJS,
     "forEach", MapForEach
   ));
 }
 
 SetUpMap();