Type Mac BNMESSQUEUE_Shutdown as void __cdecl (void)
Mac body is a frame setup and a tail JMP to BNMESSQUEUE_DeleteCritSect (0x00055829), which takes no args and returns nothing. Windows twin 0x00520200 is void (void).
Changes 1, applied together
Set prototype
mac 0x0005ad4dsignatureundefined BNMESSQUEUE_Shutdown(void)→void BNMESSQUEUE_Shutdown(void)conventionunknown→__cdecl