Add ABFD argument to sim_open call. Pass through to sim_config so

that image properties such as endianness can be checked.

More strongly document the expected behavour of each of the sim_*
interfaces.

Add default endian argument to simulator config macro
SIM_AC_OPTION_ENDIAN.  Use in sim_config.

sim/w65/interp.c

@@ -322,9 +322,10 @@ sim_kill ()
 }
 
 void
-sim_open (kind,cb,argv)
+sim_open (kind, cb, abfd, argv)
      SIM_OPEN_KIND kind;
      host_callback *cb;
+     struct _bfd *abfd;
      char **argv;
 {
 }