rb_w32_readdir    700 dir.c          # define READDIR(dir, enc) rb_w32_readdir((dir), (enc))
rb_w32_readdir     31 win32/dir.h    struct direct* rb_w32_readdir(DIR *, rb_encoding *);
rb_w32_readdir     38 win32/dir.h    #define readdir(d)   rb_w32_readdir((d), 0)