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
This goes before a snapshot, so that subsequenct patches can make the
transition without breaking the build. Disables kind checking pass, makes
parser accept both new and old-style kind annotation.
Issue #1177
While it is still technically possible to test stage 0, it is not part of any
of the main testing rules and maintaining xfail-stage0 is a chore. Nobody
should worry about how tests fare in stage0.
