Explicitly name all spawned threads

The thread name is shown in debugger as well as panic messages and this
patch makes it easier to follow a thread instead of looking through
full backtrace, by naming all spawned threads according to their
functioning.

crates/flycheck/src/lib.rs

@@ -67,7 +67,10 @@ impl FlycheckHandle {
     ) -> FlycheckHandle {
         let actor = FlycheckActor::new(id, sender, config, workspace_root);
         let (sender, receiver) = unbounded::<Restart>();
-        let thread = jod_thread::spawn(move || actor.run(receiver));
+        let thread = jod_thread::Builder::new()
+            .name("FlycheckThread".to_owned())
+            .spawn(move || actor.run(receiver))
+            .expect("failed to spawn thread");
         FlycheckHandle { sender, thread }
     }
 
@@ -266,7 +269,10 @@ impl CargoHandle {
         let child_stdout = child.stdout.take().unwrap();
         let (sender, receiver) = unbounded();
         let actor = CargoActor::new(child_stdout, sender);
-        let thread = jod_thread::spawn(move || actor.run());
+        let thread = jod_thread::Builder::new()
+            .name("CargoHandleThread".to_owned())
+            .spawn(move || actor.run())
+            .expect("failed to spawn thread");
         CargoHandle { child, thread, receiver }
     }
     fn join(mut self) -> io::Result<()> {