Could borrow checking with origins unblock sound specialization

robofinch:

we further don't want to allow specialization on lifetimes at all.

But is this really the case? Specializing on 'static seems like a perfectly valid use case. 'static is not an origin computed by the borrow checker, it's a property of the data itself. No borrow checker upgrade will change whether a string literal or an owned type is 'static. T: 'static is already a bound the solver understands.