swift234

Print the top-level names "provided" by a file along with its references.

Every name a file declares is something that another file in the same module
might depend on. The driver will need this information too to correctly
decide what files need to be rebuilt. This is part of the intra-module
dependency tracking work to implement incremental rebuilds.

This doesn't handle extensions yet, which are a bit trickier. Need to
figure out how to handle the interaction between extensions and typealiases.

Part of rdar://problem/15353101

Swift SVN r22926