Some type lambdas printed incorrectly

## Minimized code

```Scala
summon[[X] =>> (X, X)]
```

## Output

```scala
no implicit argument of type Tuple2 was found for parameter x of method summon in object DottyPredef
```

## Expectation

```scala
no implicit argument of type [X] =>> (X, X) was found for parameter x of method summon in object DottyPredef
```