fix ag_scandir() for visual studio
fix ag_scandir() for visual studio

kjk/the_silver_searcher,kjk/the_silver_searcher,kjk/the_silver_searcher,leeonix/the_silver_searcher,leeonix/the_silver_searcher,vehar/the_silver_searcher,leeonix/the_silver_searcher,vehar/the_silver_searcher,vehar/the_silver_searcher,vehar/the_silver_searcher,leeonix/the_silver_searcher,kjk/the_silver_searcher,kjk/the_silver_searcher,leeonix/the_silver_searcher,leeonix/the_silver_searcher,kjk/the_silver_searcher,vehar/the_silver_searcher,vehar/the_silver_searcher