migrate last traceback users to RTIterator, reorg

Author: duck2

utils/fasm/test/test_fasm.cpp

@@ -3,7 +3,6 @@
 
 #include "route_common.h"
 #include "route_tree_timing.h"
-#include "t_trace.h"
 #include "vpr_api.h"
 #include "vtr_util.h"
 #include "rr_metadata.h"
@@ -592,22 +591,14 @@ TEST_CASE("fasm_integration_test", "[fasm]") {
         if(!root)
             continue;
 
-        t_trace* head = traceback_from_route_tree_recurr(NULL, NULL, root.value()).first;
-        t_trace* tptr = head;
-        while(tptr != nullptr) {
-            t_trace* next = tptr->next;
-
-            if(next != nullptr && tptr->iswitch != OPEN) {
-                const auto next_inode = next->index;
-                auto iter = routing_edges.find(std::make_tuple(tptr->index, next_inode, tptr->iswitch));
+        for(auto& rt_node: root.value()) {
+            for(auto& child_node: rt_node.child_nodes()){
+                auto iter = routing_edges.find(std::make_tuple(size_t(rt_node.inode), size_t(child_node.inode), size_t(child_node.parent_switch)));
                 if (iter == routing_edges.end()) {
-                    FAIL_CHECK("source: " << tptr->index << " sink: " << next_inode << " switch:" << tptr->iswitch);
+                    FAIL_CHECK("source: " << size_t(rt_node.inode) << " sink: " << size_t(child_node.inode) << " switch:" << size_t(child_node.parent_switch));
                 }
             }
-
-            tptr = next;
         }
-        free_traceback(head);
     }
 
     // Verify CLB crossbar mux features against routed pin features.