message: Take JobQueue by-value in drain_the_queue
diff: @@ -326,7 +326,7 @@ impl<'a, 'cfg> JobQueue<'a, 'cfg> {
  /// This function will spawn off `config.jobs()` workers to build all of the
  /// necessary dependencies, in order. Freshness is propagated as far as
  /// possible along each dependency chain.
  - pub fn execute(&mut self, cx: &mut Context<'a, '_>, plan: &mut BuildPlan) -> CargoResult<()> {
  + pub fn execute(mut self, cx: &mut Context<'a, '_>, plan: &mut BuildPlan) -> CargoResult<()> {
  let _p = profile::start("executing the job graph");
  self.queue.queue_finished();
  @@ -534,7 +534,7 @@ impl<'a, 'cfg> JobQueue<'a, 'cfg> {
  }
  fn drain_the_queue(
  - &mut self,
  + mut self,
  cx: &mut Context<'a, '_>,
  plan: &mut BuildPlan,
  jobserver_helper: &HelperThread,
  