emit simple perf_hooks timings for dns operations.

```js
const { PerformanceObserver, performance } = require('perf_hooks');
const obs = new PerformanceObserver((items) => {
  const entry = items.getEntries()[0];
  console.log(entry.name, entry.duration);
  performance.clearDNS();
});
obs.observe({ entryTypes: ['dns'] });

dns.resolveAny('example.org', console.log);
```