swift234

Move the resolution of UnresolvedDeclRefExprs into the type checker.

The only visible change from this now is that diagnostics will come in
a more sensible order, because we do name resolution along with the
rest of type checking, rather than in a separate pass early
on. However, it's foundational for lazy type checking, type
refinement, and various other important features and bug fixes.



Swift SVN r7086