spsc: add note warning about inlining pop

os/src/spsc.rs

@@ -337,6 +337,9 @@ impl<T> Popper<'_, T> {
     /// resolves to a popped element. If you drop it before it has resolved,
     /// no data is lost.
     pub async fn pop(&mut self) -> T {
+        // NOTE: recognizing this function is what allows lilosdbg to show tasks
+        // waiting to pop from queues -- inlining the contained future will
+        // require debugger changes.
         self.q.pushed.until(move || self.try_pop()).await
     }
 }