Multi-line as, as?, is_a?, and other special methods cause syntax error

The following code generates a syntax error:

```crystal
x = 42.as(Int32?)
x.as(Int32
)
```

```
Error: expecting token ')', not 'NEWLINE'
```

This seems to happen with all "special" or "pseudo" methods. These also produce the issue:
`as?`, `is_a?`, `sizeof`, `pointerof`, `typeof`

Crystal v0.31.1