Setting Symbol.length to 0 according to the spec

src/bootstrapper.cc

 // Copyright 2014 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.
 
 #include "src/bootstrapper.h"
 
 #include "src/accessors.h"
 #include "src/api-natives.h"
 #include "src/code-stubs.h"
 #include "src/extensions/externalize-string-extension.h"
@@ skipping 1241 matching lines @@
 
   {
     // --- S y m b o l ---
     Handle<JSObject> prototype =
         factory->NewJSObject(isolate->object_function(), TENURED);
     Handle<JSFunction> symbol_fun =
         InstallFunction(global, "Symbol", JS_VALUE_TYPE, JSValue::kSize,
                         prototype, Builtins::kSymbolConstructor);
     symbol_fun->shared()->set_construct_stub(
         *isolate->builtins()->SymbolConstructor_ConstructStub());
-    symbol_fun->shared()->set_length(1);
+    symbol_fun->shared()->set_length(0);
     symbol_fun->shared()->DontAdaptArguments();
     native_context()->set_symbol_function(*symbol_fun);
 
     // Install the "constructor" property on the {prototype}.
     JSObject::AddProperty(prototype, factory->constructor_string(), symbol_fun,
                           DONT_ENUM);
   }
 
   {  // --- D a t e ---
     // Builtin functions for Date.prototype.
@@ skipping 2358 matching lines @@
 }
 
 
 // Called when the top-level V8 mutex is destroyed.
 void Bootstrapper::FreeThreadResources() {
   DCHECK(!IsActive());
 }
 
 }  // namespace internal
 }  // namespace v8