Remove --harmony-tostring runtime flag

src/js/messages.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
 
 var ArrayJoin;
 var Bool16x8ToString;
 var Bool32x4ToString;
 var Bool8x16ToString;
 var callSiteReceiverSymbol =
     utils.ImportNow("call_site_receiver_symbol");
 var callSiteFunctionSymbol =
     utils.ImportNow("call_site_function_symbol");
 var callSitePositionSymbol =
     utils.ImportNow("call_site_position_symbol");
 var callSiteStrictSymbol =
     utils.ImportNow("call_site_strict_symbol");
-var FLAG_harmony_tostring;
 var Float32x4ToString;
 var formattedStackTraceSymbol =
     utils.ImportNow("formatted_stack_trace_symbol");
 var GlobalObject = global.Object;
 var Int16x8ToString;
 var Int32x4ToString;
 var Int8x16ToString;
 var InternalArray = utils.InternalArray;
 var internalErrorSymbol = utils.ImportNow("internal_error_symbol");
 var ObjectDefineProperty;
@@ skipping 23 matching lines @@
   ObjectHasOwnProperty = from.ObjectHasOwnProperty;
   StringCharAt = from.StringCharAt;
   StringIndexOf = from.StringIndexOf;
   StringSubstring = from.StringSubstring;
   SymbolToString = from.SymbolToString;
   Uint16x8ToString = from.Uint16x8ToString;
   Uint32x4ToString = from.Uint32x4ToString;
   Uint8x16ToString = from.Uint8x16ToString;
 });
 
-utils.ImportFromExperimental(function(from) {
-  FLAG_harmony_tostring = from.FLAG_harmony_tostring;
-});
-
 // -------------------------------------------------------------------
 
 var GlobalError;
 var GlobalTypeError;
 var GlobalRangeError;
 var GlobalURIError;
 var GlobalSyntaxError;
 var GlobalReferenceError;
 var GlobalEvalError;
 
 
 function NoSideEffectsObjectToString() {
   if (IS_UNDEFINED(this)) return "[object Undefined]";
   if (IS_NULL(this)) return "[object Null]";
   var O = TO_OBJECT(this);
   var builtinTag = %_ClassOf(O);
-  var tag;
-  if (FLAG_harmony_tostring) {
-    tag = %GetDataProperty(O, toStringTagSymbol);
-    if (!IS_STRING(tag)) {
-      tag = builtinTag;
-    }
-  } else {
+  var tag = %GetDataProperty(O, toStringTagSymbol);
+  if (!IS_STRING(tag)) {
     tag = builtinTag;
   }
   return `[object ${tag}]`;
 }
 
 function IsErrorObject(obj) {
   return HAS_PRIVATE(obj, stackTraceSymbol);
 }
 
 function NoSideEffectsErrorToString() {
@@ skipping 900 matching lines @@
 utils.Export(function(to) {
   to.ErrorToString = ErrorToString;
   to.MakeError = MakeError;
   to.MakeRangeError = MakeRangeError;
   to.MakeSyntaxError = MakeSyntaxError;
   to.MakeTypeError = MakeTypeError;
   to.MakeURIError = MakeURIError;
 });
 
 });