[proxies] Implement the Proxy constructor in C++ fully.

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 2131 matching lines @@
   SIMD128_TYPES(SIMD128_INSTALL_FUNCTION)
 #undef SIMD128_INSTALL_FUNCTION
 }
 
 
 void Genesis::InitializeGlobal_harmony_proxies() {
   if (!FLAG_harmony_proxies) return;
   Handle<JSGlobalObject> global(
       JSGlobalObject::cast(native_context()->global_object()));
   Isolate* isolate = global->GetIsolate();
-  Handle<JSFunction> proxy_fun =
-      InstallFunction(global, "Proxy", JS_PROXY_TYPE, JSProxy::kSize,
-                      isolate->initial_object_prototype(), Builtins::kIllegal);
+  Handle<JSFunction> proxy_fun = InstallFunction(
+      global, "Proxy", JS_PROXY_TYPE, JSProxy::kSize,
+      isolate->initial_object_prototype(), Builtins::kProxyConstructor);
   // TODO(verwaest): Set to null in InstallFunction.
   proxy_fun->initial_map()->set_prototype(isolate->heap()->null_value());
   proxy_fun->shared()->set_construct_stub(
-      *isolate->builtins()->JSBuiltinsConstructStub());
+      *isolate->builtins()->ProxyConstructor_ConstructStub());
+  proxy_fun->shared()->set_internal_formal_parameter_count(2);
+  proxy_fun->shared()->set_length(2);
   native_context()->set_proxy_function(*proxy_fun);
 }
 
 
 Handle<JSFunction> Genesis::InstallInternalArray(Handle<JSObject> target,
                                                  const char* name,
                                                  ElementsKind elements_kind) {
   // --- I n t e r n a l   A r r a y ---
   // An array constructor on the builtins object that works like
   // the public Array constructor, except that its prototype
@@ skipping 1026 matching lines @@
 }
 
 
 // Called when the top-level V8 mutex is destroyed.
 void Bootstrapper::FreeThreadResources() {
   DCHECK(!IsActive());
 }
 
 }  // namespace internal
 }  // namespace v8