async_wrap: return uid as double

Don't truncate the int64_t uid_ of an AsyncWrap instance by passing it
to Integer::New(). Instead allow the entire 2^53 integer space within
the double to be used by using Number::New().

src/async-wrap-inl.h

@@ -40,14 +40,14 @@ inline AsyncWrap::AsyncWrap(Environment* env,
   v8::HandleScope scope(env->isolate());
 
   v8::Local<v8::Value> argv[] = {
-    v8::Integer::New(env->isolate(), get_uid()),
+    v8::Number::New(env->isolate(), get_uid()),
     v8::Int32::New(env->isolate(), provider),
     Null(env->isolate()),
     Null(env->isolate())
   };
 
   if (parent != nullptr) {
-    argv[2] = v8::Integer::New(env->isolate(), parent->get_uid());
+    argv[2] = v8::Number::New(env->isolate(), parent->get_uid());
     argv[3] = parent->object();
   }
 
@@ -72,7 +72,7 @@ inline AsyncWrap::~AsyncWrap() {
   v8::Local<v8::Function> fn = env()->async_hooks_destroy_function();
   if (!fn.IsEmpty()) {
     v8::HandleScope scope(env()->isolate());
-    v8::Local<v8::Value> uid = v8::Integer::New(env()->isolate(), get_uid());
+    v8::Local<v8::Value> uid = v8::Number::New(env()->isolate(), get_uid());
     v8::TryCatch try_catch(env()->isolate());
     v8::MaybeLocal<v8::Value> ret =
         fn->Call(env()->context(), v8::Null(env()->isolate()), 1, &uid);

src/async-wrap.cc

@@ -19,6 +19,7 @@ using v8::Integer;
 using v8::Isolate;
 using v8::Local;
 using v8::MaybeLocal;
+using v8::Number;
 using v8::Object;
 using v8::RetainedObjectInfo;
 using v8::TryCatch;
@@ -198,7 +199,7 @@ Local<Value> AsyncWrap::MakeCallback(const Local<Function> cb,
 
   Local<Function> pre_fn = env()->async_hooks_pre_function();
   Local<Function> post_fn = env()->async_hooks_post_function();
-  Local<Value> uid = Integer::New(env()->isolate(), get_uid());
+  Local<Value> uid = Number::New(env()->isolate(), get_uid());
   Local<Object> context = object();
   Local<Object> domain;
   bool has_domain = false;