Issue Description:

The precondition in Collection.distance that reads “Only BidirectionalCollections can have end come before start” fires even for {{BidirectionalCollection}} models unless the implementor of the collection is hyper-vigilant and implements their own distance method.

We could solve this problem by adding a default implementation of distance for BidirectionalCollections, but we're already doing a test/branch even on collections that are non-bidirectional, to detect the precondition violation. We might as well just do the right thing in all cases.

#34981 takes a first crack at an implementation.