message: Avoid an if_same_then_else warning
  Summary: This warning only gets triggered in newer versions of the nightly compiler, but generally it's quite a useful warning, so adapt to its changes.
diff: @@ -540,10 +540,9 @@ mod flame {
  // New frame, enter it.
  let id = self.ids.get_value(*function);
  self.current = Some(frame.push(id));
  - } else if let Some(..) = x.downcast_ref::<CallExit<NeedsDrop>>() {
  - // End of frame, exit!
  - self.current = frame.pop();
  - } else if let Some(..) = x.downcast_ref::<CallExit<NoDrop>>() {
  + } else if x.downcast_ref::<CallExit<NeedsDrop>>().is_some()
  + || x.downcast_ref::<CallExit<NoDrop>>().is_some()
  + {
  // End of frame, exit!
  self.current = frame.pop();
  } else {
  