rollup merge of #22435: aturon/final-stab-thread

Conflicts:
	src/test/bench/rt-messaging-ping-pong.rs
	src/test/bench/rt-parfib.rs
	src/test/bench/task-perf-spawnalot.rs

src/libtest/lib.rs

@@ -879,7 +879,7 @@ pub fn run_test(opts: &TestOpts,
                       monitor_ch: Sender<MonitorMsg>,
                       nocapture: bool,
                       testfn: Thunk) {
-        Thread::spawn(move || {
+        thread::spawn(move || {
             let (tx, rx) = channel();
             let mut reader = ChanReader::new(rx);
             let stdout = ChanWriter::new(tx.clone());