Remove all harmony runtime flags which shipped in M51

src/js/symbol.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 GlobalSymbol = global.Symbol;
 var hasInstanceSymbol = utils.ImportNow("has_instance_symbol");
 var isConcatSpreadableSymbol =
     utils.ImportNow("is_concat_spreadable_symbol");
 var iteratorSymbol = utils.ImportNow("iterator_symbol");
 var MakeTypeError;
+var matchSymbol = utils.ImportNow("match_symbol");
+var replaceSymbol = utils.ImportNow("replace_symbol");
+var searchSymbol = utils.ImportNow("search_symbol");
+var speciesSymbol = utils.ImportNow("species_symbol");
+var splitSymbol = utils.ImportNow("split_symbol");
 var toPrimitiveSymbol = utils.ImportNow("to_primitive_symbol");
 var toStringTagSymbol = utils.ImportNow("to_string_tag_symbol");
 var unscopablesSymbol = utils.ImportNow("unscopables_symbol");
 
 utils.Import(function(from) {
   MakeTypeError = from.MakeTypeError;
 });
 
 // -------------------------------------------------------------------
 
@@ skipping 41 matching lines @@
   if (!IS_SYMBOL(symbol)) throw MakeTypeError(kSymbolKeyFor, symbol);
   return %SymbolRegistry().keyFor[symbol];
 }
 
 // -------------------------------------------------------------------
 
 utils.InstallConstants(GlobalSymbol, [
   "hasInstance", hasInstanceSymbol,
   "isConcatSpreadable", isConcatSpreadableSymbol,
   "iterator", iteratorSymbol,
-  // TODO(yangguo): expose when implemented.
-  // "match", matchSymbol,
-  // "replace", replaceSymbol,
-  // "search", searchSymbol,
-  // "split, splitSymbol,
+  "match", matchSymbol,
+  "replace", replaceSymbol,
+  "search", searchSymbol,
+  "species", speciesSymbol,
+  "split", splitSymbol,
   "toPrimitive", toPrimitiveSymbol,
   "toStringTag", toStringTagSymbol,
   "unscopables", unscopablesSymbol,
 ]);
 
 utils.InstallFunctions(GlobalSymbol, DONT_ENUM, [
   "for", SymbolFor,
   "keyFor", SymbolKeyFor
 ]);
 
@@ skipping 10 matching lines @@
 ]);
 
 // -------------------------------------------------------------------
 // Exports
 
 utils.Export(function(to) {
   to.SymbolToString = SymbolToString;
 })
 
 })