fails:IO#lineno raises an IOError on a write-only stream
fails:IO#lineno raises an IOError on a duplexed stream with the read side closed
fails:IO#lineno= raises an IOError on a write-only stream
fails:IO#lineno= raises an IOError on a duplexed stream with the read side closed
fails:IO#lineno= raises TypeError if cannot convert argument to Integer implicitly
