[Bug] usb_util.h针对IAR8.50.9的宏定义__USED（#define __USED __attribute__((used))）无效，会被IAR优化

[skllii]

RT-Thread Version

master

Hardware Type/Architectures

ARM contex-M4

Develop Toolchain

IAR

Describe the bug

usb_util.h 宏定义__USED针对__ICCARM_V8的定义是无效的，导致CLASS_INFO_DEFINE失效��会被编译器优化。

__ICCARM_V8应该使用__root
#define __USED __root

Other additional context

No response