Fix Default for rtic_sync::signal

rtic-sync/src/signal.rs

@@ -12,12 +12,17 @@ enum Store<T> {
 }
 
 /// A "latest only" value store with unlimited writers and async waiting.
-#[derive(Default)]
 pub struct Signal<T: Copy> {
     waker: CriticalSectionWakerRegistration,
     store: UnsafeCell<Store<T>>,
 }
 
+impl<T: Copy> Default for Signal<T> {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 unsafe impl<T: Copy> Send for Signal<T> {}
 unsafe impl<T: Copy> Sync for Signal<T> {}