[8.0.0 Release] Release Candidate 2 source, docs, and binaries available

Hello everyone,

Source, docs, and some binaries for LLVM-8.0.0-rc2 are now available
at https://prereleases.llvm.org/8.0.0/#rc2

More binaries will be added as they become available.

Please try it out and report any problems as bugs marked as blockers
of https://llvm.org/pr40331

Thanks,
Hans