swift234

[Accessibility] Public variables cannot have private types.

This does not yet handle variables with inferred types, since those don't
have TypePatterns.

There is some nasty propagation of @public into the stdlib because of this
one, mainly because Foundation needs access to some of the implementation
details of Array and Dictionary. We may want to try to improve this later
(or just build Foundation with -disable-access-control if it comes to that).

Swift SVN r19432