Ported nearest_point() and nearest_point_index()

lib/Slic3r/ExtrusionPath/Collection.pm

@@ -23,7 +23,7 @@ sub chained_path {
     while (@my_paths) {
         # find nearest point
         my $start_index = defined $start_near
-            ? Slic3r::Geometry::nearest_point_index($start_near, $endpoints)
+            ? $start_near->nearest_point_index($endpoints)
             : 0;
 
         my $path_index = int($start_index/2);