This involved adding 'copy' to more generics than I hoped, but an
experiment with making it implicit showed that that way lies madness --
unless enforced, you will not remember to mark functions that don't
copy as not requiring copyable kind.
Issue #1177
You almost never want a function with pinned type params. For
types, objects, resources, and tags, pinned types are actually often
more sane. For most of these, shared rarely makes sense. Only tricky
case is objs -- you'll have to think about the kinds you want there.
Issue #1076
