…ck` handler

Currently, if you render `next/link` like

```ts
<Link>
  <CustomComponent />
</Link>
```

and have 

```tsx
interface Props {
  onClick?: () => void; // <— note we're not passing event as an argument
}

function CustomComponent({ onClick }: Props) {
  return <div onClick={() => onClick?.()}>Hello</div>
}
```

It'll result in error

```
link.js?f421:21 Uncaught TypeError: Cannot read property 'defaultPrevented' of undefined
```