message: Upgrade to crossbeam-utils's -new 0.5 API
diff: @@ -7,7 +7,7 @@ use std::sync::mpsc::{channel, Receiver, Sender};
  use std::sync::Arc;
  use crossbeam_utils;
  -use crossbeam_utils::scoped::Scope;
  +use crossbeam_utils::thread::Scope;
  use jobserver::{Acquired, HelperThread};
  use core::profiles::Profile;
  @@ -166,7 +166,7 @@ impl<'a> JobQueue<'a> {
  srv.start(move |msg| drop(tx2.send(Message::FixDiagnostic(msg))))
  });
  - crossbeam_utils::scoped::scope(|scope| self.drain_the_queue(cx, plan, scope, &helper))
  + crossbeam_utils::thread::scope(|scope| self.drain_the_queue(cx, plan, scope, &helper))
  }
  fn drain_the_queue(
  