Avoid deprecation warnings in Nan::JSON

This only affects older versions which do not support async_hooks
but it seemed easiest to set them up anyway.

nan_json.h

@@ -134,14 +134,17 @@ class JSON {
 #if NAN_JSON_H_NEED_PARSE
   inline v8::Local<v8::Value> parse(v8::Local<v8::Value> arg) {
     assert(!parse_cb_.IsEmpty() && "parse_cb_ is empty");
-    return parse_cb_.Call(1, &arg);
+    AsyncResource resource("nan:JSON.parse");
+    return parse_cb_.Call(1, &arg, &resource).FromMaybe(v8::Local<v8::Value>());
   }
 #endif  // NAN_JSON_H_NEED_PARSE
 
 #if NAN_JSON_H_NEED_STRINGIFY
   inline v8::Local<v8::Value> stringify(v8::Local<v8::Value> arg) {
     assert(!stringify_cb_.IsEmpty() && "stringify_cb_ is empty");
-    return stringify_cb_.Call(1, &arg);
+    AsyncResource resource("nan:JSON.stringify");
+    return stringify_cb_.Call(1, &arg, &resource)
+        .FromMaybe(v8::Local<v8::Value>());
   }
 
   inline v8::Local<v8::Value> stringify(v8::Local<v8::Value> arg,
@@ -153,7 +156,9 @@ class JSON {
       Nan::Null(),
       gap
     };
-    return stringify_cb_.Call(3, argv);
+    AsyncResource resource("nan:JSON.stringify");
+    return stringify_cb_.Call(3, argv, &resource)
+        .FromMaybe(v8::Local<v8::Value>());
   }
 #endif  // NAN_JSON_H_NEED_STRINGIFY
 };