Fix RWC Runner (#10420)

* Use /// <reference types

* Don't report an errors if it comes from lib.d.ts

scripts/ior.ts

@@ -1,4 +1,4 @@
-/// <reference path="../src/harness/external/node.d.ts" />
+/// <reference types="node"/>
 
 import fs = require('fs');
 import path = require('path');