Add the glibc-compatible d_fileno.

d_ino is the POSIX name, but glibc also offers d_fileno, and
that's what strace is using.

Change-Id: I3fadbe7a64700b42e78c7f4631620e864d43147b

libc/include/dirent.h

@@ -53,6 +53,7 @@ struct dirent {
   unsigned char    d_type;
   char             d_name[256];
 };
+#define d_fileno d_ino
 #define dirent64 dirent
 
 typedef struct DIR DIR;