Add (||.) and (&&.), and handle their non-bool use correctly

[Tarmil]

We have "dotted" operators that inline to plain JS operators for all operators except these two.

The main reason to use them would be to use their short-circuiting property for something else than booleans (eg a || b returns a if it is truthy, otherwise b, neither of which are necessarily booleans). This requires support in the breaker, which currently assumes that operands to these two operators are booleans.