Convert 'fill_directory()' to use the pathspec struct interface from
using the '_raw' entry in the pathspec struct.
Signed-off-by: Brandon Williams <bmwill@google.com> Reviewed-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>