[5.0.0 Release] Release Candidate 1 source and binaries available

Hello all,

Source, binaries and docs for LLVM-5.0.0-rc1 are now available at
http://prereleases.llvm.org/5.0.0/#rc1

Please try it out, run tests, builds your favourite projects and file
bugs about anything that needs to be fixed (including docs!), marking
them blockers of http://llvm.org/pr33849.

Cheers,
Hans