test: fix up weakref.cc after v8 api change

test/gc/node_modules/weak/src/weakref.cc

@@ -134,8 +134,8 @@ void AddCallback(Handle<Object> proxy, Handle<Function> callback) {
 }
 
 
-void TargetCallback(Persistent<Value> target, void* arg) {
-  HandleScope scope;
+void TargetCallback(Isolate* isolate, Persistent<Value> target, void* arg) {
+  HandleScope scope(isolate);
 
   assert(target.IsNearDeath());
 
@@ -187,7 +187,9 @@ Handle<Value> Create(const Arguments& args) {
   cont->proxy = Persistent<Object>::New(proxyClass->NewInstance());
   cont->proxy->SetAlignedPointerInInternalField(0, cont);
 
-  cont->target.MakeWeak(cont, TargetCallback);
+  cont->target.MakeWeak(Isolate::GetCurrent(),
+                        static_cast<void*>(cont),
+                        TargetCallback);
 
   if (args.Length() >= 2) {
     AddCallback(cont->proxy, Handle<Function>::Cast(args[1]));