Channel tuples not highlighted correctly

[nathansizemore]

When creating a channel:

let (tx, rx): (Sender<Vec<u8>>, Receiver<Vec<u8>>) = channel();

The brackets are not highlighted the same. Sender's are blank while the Receiver's get highlighted.

[zargony]

Seems like the Receiver's type params are not recognized and classified as operators instead.

[zargony]

With fd5447b, sender and receiver types are now highlighted the same. But they're mistakenly recognized as operators since we still have incomplete syntax rules for type hints in let statements.