Added getState() to TaskHandle for comparison.

source/mijin/async/coroutine.hpp

@@ -112,6 +112,8 @@ public:
         return !state_.expired();
     }
 
+    [[nodiscard]] const void* getState() const MIJIN_NOEXCEPT { return state_.lock().get(); }
+
     inline void cancel() const MIJIN_NOEXCEPT;
     [[nodiscard]] inline Optional<std::source_location> getLocation() const MIJIN_NOEXCEPT;
 #if MIJIN_COROUTINE_ENABLE_DEBUG_INFO