Invalid JS minification

Input:

```js
if (true) {
  const checkData = setInterval(() => {
    clearInterval(checkData);
  }, 100);
}
```

Output:

```js
!0&&setInterval(()=>{clearInterval(checkData)},100)
```

Expected:

```js
if (!0) {
const e=setInterval(()=>{clearInterval(e)},100})
}
```

The name `checkData` is dropped, resulting in invalid code.

See https://github.com/spotlightpa/poor-richard/pull/1008/files