If we never evaluate under Delay at all, we won't inline interface
methods, which means productive things defined in an interface can never
be today. So, make sure to set the tcinline flag before quoting the
Delayed closure.
As in Idris 1 - if an interface declares a method as total or covering,
then all implementations have to satisfy that.
Temporarily turn off %default directive again, at least until totality
checking works as it should (this is probably better than removing it
from various places because I'll forget to put them back)
