Fix restoring permissions of intermediate directories with --skip-old-files

Fix restoring permissions of intermediate directories with --skip-old-files

Detailed bug report: https://savannah.gnu.org/bugs/index.php?66774

* src/extract.c (update_interdir_set_stat): New function.
(extract_dir): If the directory already exists, check if it
has been created as intermediate directory earlier.  If so,
update its delayed_set_stat data from archive.

* tests/Makefile.am: Add new testcase.
* tests/testsuite.at: Add new testcase.
* tests/extrac28.at: New file.