Connect module instance arrays MSB to MSB.

When a bit port of a module instance is connected to a vector
argument, the MSB module instance should be connected to the MSB
of the vector argument. This matters only in the rare case that
the %m is used. It also makes wave dumps come out right.

elab_scope.cc

@@ -741,7 +741,11 @@ void PGModule::elaborate_scope_mod_(Design*des, Module*mod, NetScope*sc) const
 
 	/* Stash the instance array of scopes into the parent
 	   scope. Later elaboration passes will use this vector to
-	   further elaborate the array. */
+	   further elaborate the array.
+
+	   Note that the array is ordered from LSB to MSB. We will use
+	   that fact in the main elaborate to connect things in the
+	   correct order. */
       sc->instance_arrays[get_name()] = instances;
 }
 

elaborate.cc

@@ -1037,7 +1037,9 @@ void PGModule::elaborate_mod_(Design*des, Module*rmod, NetScope*scope) const
 	    unsigned prts_vector_width = 0;
 
 	    for (unsigned inst = 0 ;  inst < instance.count() ;  inst += 1) {
-		  NetScope*inst_scope = instance[inst];
+		    // Scan the instances from MSB to LSB. The port
+		    // will be assembled in that order as well.
+		  NetScope*inst_scope = instance[instance.count()-inst-1];
 
 		    // Scan the module sub-ports for this instance...
 		  for (unsigned ldx = 0 ;  ldx < mport.count() ;  ldx += 1) {