Buildmaster restart 08.20.2017

Hello everyone,
LLVM buildmasters (both main and staging) will be restarted in 2 hours
(~3:00 AM PDT).

Both buildmasters were updated and currently are up and running.

Hello all, ps4-buildslave1a is currently down. We are detecting the
cause and will fix it ASAP. I will inform when it is accessible again.

Sorry for the inconvenience.

ps4-buildslave1a is back.