Parser error when selecting from a symbolic term

## Compiler version

v3.0.0-RC3
## Minimized code

```Scala
object + {
  val x = 1
}

object Check {
  val y = +.x  
}
```

## Output

```scala
expression expected but '.' found
```

## Expectation
Should work like in Scala 2. Adding backticks around `+` does not help.