Fix powermacg5 build failure.

server-tools/instance-manager/angel.cc:
  Include my_dir.h because MacOS defines mode constants
  (S_IRUSR, S_IWUSR, ...) in sys/stat.h.

server-tools/instance-manager/angel.cc

@@ -26,6 +26,7 @@
 
 #include "my_global.h"
 #include "my_alarm.h"
+#include "my_dir.h"
 #include "my_sys.h"
 
 /* Include other IM files. */