add flat idx to pb_graph_node , populate in alloc_and_load_pb_graph#2590

vaughnbetz merged 3 commits intomasterverilog-to-routing/vtr-verilog-to-routing:masterfrom

add_flat_site_index_to_pg_graph_nodeverilog-to-routing/vtr-verilog-to-routing:add_flat_site_index_to_pg_graph_nodeCopy head branch name to clipboard