sim: namespace sim_machs

We want to do a single build with all arches in one binary which means
we need to namespace sim_machs on a per-arch basis.  Move it from a
global variable to the sim description structure so it can be setup at
runtime.

Changing the SIM_MODEL->num from an enum to an int is unfortunate, but
we specifically don't want to maintain a centralized list anymore, and
this was never used directly in common code, just passed to per-arch
callbacks.

sim/m32r/sim-if.c

@@ -44,6 +44,8 @@ free_state (SIM_DESC sd)
   sim_state_free (sd);
 }
 
+extern const SIM_MACH * const m32r_sim_machs[];
+
 /* Create an instance of the simulator.  */
 
 SIM_DESC
@@ -55,6 +57,7 @@ sim_open (SIM_OPEN_KIND kind, host_callback *callback, struct bfd *abfd,
   int i;
 
   /* Set default options before parsing user options.  */
+  STATE_MACHS (sd) = m32r_sim_machs;
   current_alignment = STRICT_ALIGNMENT;
   current_target_byte_order = BFD_ENDIAN_BIG;