[SynopticInstances::] Instances.

To compile the main/synoptic/instances submodule.

@ Our inventory |inv| already contains a list |inv->instance_nodes| of all packages
in the tree with type |_instance|.

For the moment, at least, it seems too ambitious to dynamically renumber instances
in the linking stage. Until then, this section is something of a placeholder,
making only a debugging function.

=
void SynopticInstances::compile(inter_tree *I, pipeline_step *step, tree_inventory *inv) {
	if (InterNodeList::array_len(inv->instance_nodes) > 0)
		InterNodeList::array_sort(inv->instance_nodes, MakeSynopticModuleStage::module_order);
	@<Define SHOWMEINSTANCEDETAILS function@>;
}

@<Define SHOWMEINSTANCEDETAILS function@> =
	inter_name *iname = HierarchyLocations::iname(I, SHOWMEINSTANCEDETAILS_HL);
	Synoptic::begin_function(I, iname);
	inter_symbol *which_s = Synoptic::local(I, I"which", NULL);
	inter_symbol *na_s = Synoptic::local(I, I"na", NULL);
	inter_symbol *t_0_s = Synoptic::local(I, I"t_0", NULL);
	for (int i=0; i<InterNodeList::array_len(inv->instance_nodes); i++) {
		inter_package *pack = PackageInstruction::at_this_head(inv->instance_nodes->list[i].node);
		inter_symbol *showme_s = Metadata::optional_symbol(pack, I"^showme_fn");
		if (showme_s) {
			Produce::inv_primitive(I, STORE_BIP);
			Produce::down(I);
				Produce::ref_symbol(I, K_value, na_s);
				Produce::inv_call_symbol(I, showme_s);
				Produce::down(I);
					Produce::val_symbol(I, K_value, which_s);
					Produce::val_symbol(I, K_value, na_s);
					Produce::val_symbol(I, K_value, t_0_s);
				Produce::up(I);
			Produce::up(I);
		}
	}	
	Produce::inv_primitive(I, RETURN_BIP);
	Produce::down(I);		
		Produce::val_symbol(I, K_value, na_s);
	Produce::up(I);		
	Synoptic::end_function(I, step, iname);