libmango: types: add macro to define a kern_msg_handle_t

kernel/channel.c

@@ -362,11 +362,11 @@ extern kern_status_t channel_write_msg(
 
 	kern_status_t status = vm_region_memmove_v(
 		dest_region,
-		0,
+		offset,
 		msg->msg_resp.msg_data,
 		msg->msg_resp.msg_data_count,
 		src_region,
-		offset,
+		0,
 		src_iov,
 		src_iov_count,
 		VM_REGION_COPY_ALL,

libmango/include/mango/types.h

@@ -28,6 +28,11 @@
 		.io_base = (virt_addr_t)(p),                                   \
 		.io_len = (len),                                               \
 	}
+#define MSG_HANDLE(mode, value)                                                \
+	{                                                                      \
+		.hnd_mode = (mode),                                            \
+		.hnd_value = (value),                                          \
+	}
 #define MSG(data, data_count, handles, handles_len)                            \
 	{                                                                      \
 		.msg_data = (data),                                            \