This uses the new layout of the upstream repository, which was recently
migrated to GitHub, and converted into a "monorepo". That is, most of
the earlier separate sub-projects with their own branches and tags were
consolidated into one top-level directory, and are now branched and
tagged together.
Updating the vendor area to match this layout is next.
ludes minor changes relative to upstream, for compatibility with
FreeBSD's in-tree LLVM 3.3:
- Reverted LLDB r191806, restoring use of previous API.
- Reverted part of LLDB r189317, restoring previous enum names.
- Work around missing LLVM r192504, using previous registerEHFrames API
(limited functionality).
- Removed PlatformWindows header include and init/terminate calls.
Sponsored by: DARPA, AFRL
