cmake STRUCT_DIRENT_HAS_D_NAMLEN examples

alibaba/AliSQL configure.cmake :1226 

CHECK_STRUCT_HAS_MEMBER("struct dirent" d_namlen "dirent.h"  STRUCT_DIRENT_HAS_D_NAMLEN)

alibaba/AliSQLBackup configure.cmake :1140 

CHECK_STRUCT_HAS_MEMBER("struct dirent" d_namlen "dirent.h"  STRUCT_DIRENT_HAS_D_NAMLEN)