call original fsBinding.open when collecting ReadFileContext proto to avoid creating open handle

Author: jloleysens

lib/readfilecontext.js

@@ -17,6 +17,7 @@ exports.getReadFileContextPrototype = function() {
   let proto;
   fsBinding.open = (_path, _flags, _mode, req) => {
     proto = Object.getPrototypeOf(req.context);
+    originalOpen.apply(fsBinding, [_path, _flags, _mode, req]);
   };
 
   fs.readFile('/ignored.txt', () => {});