There are probably more.

Fundamentally, I’m not sure what this flag is supposed to mean.  AFAICS,
there’s no way to create a non-contiguous bytevector (or SRFI-4 vector).

This flag was added in 7ed54fd36d2e381aa46ef8a7d2fc13a6776b573a.  My
guess is that it was part of plan that wasn’t carried out in the end.

Andy, thoughts?  :-)

Thanks,
Ludo’.