Moved the "sim_open" call to after the callback initialisation. This

is to allow the simulator initialisation code to make use of the host
callback facilities. Had discussed this with sac, and it should be a
harmless change since none of the other simulators really make use of
the call, and it does not return a result.

gdb/remote-sim.c

@@ -217,11 +217,12 @@ gdbsim_open (args, from_tty)
 {
   if (sr_get_debug ())
     printf_filtered ("gdbsim_open: args \"%s\"\n", args ? args : "(null)");
-  sim_open (args);
 
   sim_set_callbacks (&default_callback);
   default_callback.init (&default_callback);
 
+  sim_open (args);
+
   push_target (&gdbsim_ops);
   target_fetch_registers (-1);
   printf_filtered ("Connected to the simulator.\n");