dpl: avoid improve_placement crashes on no-site macros( improve_placement core dump)#9863

duckkkkkkkkking wants to merge 1 commit intoThe-OpenROAD-Project:masterThe-OpenROAD-Project/OpenROAD:masterfrom

duckkkkkkkkking:fix/improve-placement-no-site-crashduckkkkkkkkking/OpenROAD_duck:fix/improve-placement-no-site-crashCopy head branch name to clipboard