message: inline drop traits to impove the speed
diff: //! A shareable mutable interrupt-safe memory location with
  //! dynamically checked borrow rules
  //!
  -//! In principle it embeds `RefCell<T>` from the core library in a new object.
  +//! In principle it embeds `RefCell<T>` from the core library into a new object.
  //! By borrowing the reference, interrupts are automatically disabled to support
  //! the usage within an interrupt handler.
  @@ -40,6 +40,7 @@ impl<T> Deref for Ref<'_, T> {
  }
  impl<T> Drop for Ref<'_, T> {
  + #[inline]
  fn drop(&mut self) {
  irq::nested_enable(self.irq);
  }
  @@ -76,6 +77,7 @@ impl<T> DerefMut for RefMut<'_, T> {
  }
  impl<T> Drop for RefMut<'_, T> {
  + #[inline]
  fn drop(&mut self) {
  irq::nested_enable(self.irq);
  }
  