Add hint to avoid bugprone-use-after-move warnings

Makes clang (and GCC) consider item.Clear() a reinitialisation of a moved variable - see https://clang.llvm.org/extra/clang-tidy/checks/bugprone-use-after-move.html#reinitialization

Source/cpp.hint

@@ -0,0 +1,7 @@
+// Hint files help the Visual Studio IDE interpret Visual C++ identifiers
+// such as names of functions and macros.
+// For more information see https://go.microsoft.com/fwlink/?linkid=865984
+#define DVL_ALWAYS_INLINE
+#define DVL_ATTRIBUTE_HOT
+#define DVL_API_FOR_TEST
+#define DVL_REINITIALIZES

Source/items.h

@@ -245,7 +245,7 @@ struct Item {
 	/**
 	 * @brief Resets the item so isEmpty() returns true without needing to reinitialise the whole object
 	 */
-	void Clear()
+	DVL_REINITIALIZES void Clear()
 	{
 		this->_itype = ItemType::None;
 	}

Source/utils/attributes.h

@@ -42,3 +42,11 @@
 #else
 #define DVL_API_FOR_TEST
 #endif
+
+#if defined(__clang__)
+#define DVL_REINITIALIZES [[clang::reinitializes]]
+#elif DVL_HAVE_ATTRIBUTE(reinitializes)
+#define DVL_REINITIALIZES __attribute__((reinitializes))
+#else
+#define DVL_REINITIALIZES
+#endif