9696 add /etc/system.d support
Portions contributed by: Andy Fiddaman <andy@omniosce.org>
Reviewed by: Hans Rosenfeld <hans.rosenfeld@joyent.com>
Reviewed by: Peter Tribble <peter.tribble@gmail.com>
Reviewed by: C Fraire <cfraire@me.com>
Reviewed by: Toomas Soome <tsoome@me.com>

*** 544,553 ****
--- 544,554 ----
   * global function and data declarations
   */
  extern kmutex_t mod_lock;
  
  extern char *systemfile;
+ extern char *self_assembly;
  extern char **syscallnames;
  extern int moddebug;
  
  /*
   * this is the head of a doubly linked list.  Only the next and prev