[builtins] Migrate Number.parseFloat to a TurboFan builtin.

src/js/v8natives.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.
 
 (function(global, utils) {
 
 %CheckIsBootstrapping();
 
 // ----------------------------------------------------------------------------
 // Imports
@@ skipping 34 matching lines @@
   }
 
   if (%_HasCachedArrayIndex(string) &&
       (radix == 0 || radix == 10)) {
     return %_GetCachedArrayIndex(string);
   }
   return %StringParseInt(string, radix);
 }
 
 
-// ES6 18.2.4 parseFloat(string)
-function GlobalParseFloat(string) {
-  // 1. Let inputString be ? ToString(string).
-  string = TO_STRING(string);
-  if (%_HasCachedArrayIndex(string)) return %_GetCachedArrayIndex(string);
-  return %StringParseFloat(string);
-}
-
-
 // ----------------------------------------------------------------------------
 
 // Set up global object.
 var attributes = DONT_ENUM | DONT_DELETE | READ_ONLY;
 
 utils.InstallConstants(global, [
   // ES6 18.1.1
   "Infinity", INFINITY,
   // ES6 18.1.2
   "NaN", NaN,
   // ES6 18.1.3
   "undefined", UNDEFINED,
 ]);
 
 // Set up non-enumerable function on the global object.
 utils.InstallFunctions(global, DONT_ENUM, [
   "parseInt", GlobalParseInt,
-  "parseFloat", GlobalParseFloat,
 ]);
 
 
 // ----------------------------------------------------------------------------
 // Object
 
 // ES6 19.1.3.5 Object.prototype.toLocaleString([reserved1 [,reserved2]])
 function ObjectToLocaleString() {
   CHECK_OBJECT_COERCIBLE(this, "Object.prototype.toLocaleString");
   return this.toString();
@@ skipping 114 matching lines @@
   // --- Harmony constants (no spec refs until settled.)
 
   "MAX_SAFE_INTEGER", 9007199254740991,
   "MIN_SAFE_INTEGER", -9007199254740991,
   "EPSILON", 2.220446049250313e-16,
 ]);
 
 // Harmony Number constructor additions
 utils.InstallFunctions(GlobalNumber, DONT_ENUM, [
   "parseInt", GlobalParseInt,
-  "parseFloat", GlobalParseFloat
 ]);
 
 
 
 // ----------------------------------------------------------------------------
 // Iterator related spec functions.
 
 // ES6 7.4.1 GetIterator(obj, method)
 function GetIterator(obj, method) {
   if (IS_UNDEFINED(method)) {
@@ skipping 16 matching lines @@
   to.GetIterator = GetIterator;
   to.GetMethod = GetMethod;
   to.ObjectHasOwnProperty = GlobalObject.prototype.hasOwnProperty;
 });
 
 %InstallToContext([
   "object_value_of", ObjectValueOf,
 ]);
 
 })