Cleaned up a unused member variable in Debugger.

Added the start of Host specific launch services, though it currently isn't
hookup up to anything. We want to be able to launch a process and use the
native launch services to launch an app like it would be launched by the
user double clicking on the app. We also eventually want to be able to run
a command line app in a newly spawned terminal to avoid terminal sharing.

Fixed an issue with the new DWARF forward type declaration stuff. A crasher
was found that was happening when trying to properly expand the forward
declarations.

llvm-svn: 115213