Add type regions. Untyped lexical vars not an internal error. svn: r18374 original commit: 8e3a67936eeb14fc08279a075966f93e35209f23
svn: r18333 original commit: 3d95ef650c1908d79f9b2bf5e3086322cdb494bc
svn: r17814 original commit: e65535c88037da8c21876c9c4a7fcd62efdbe9d4