xgettext: Fix some test failures on MSVC.
* gettext-tools/src/locating-rule.c: Include <dirent.h> always.
(HAVE_DIR): Remove macro.
(locating_rule_list_add_from_directory): Don't test HAVE_DIR.
* gettext-tools/src/msginit.c: Include <dirent.h> always.
(HAVE_DIR): Remove macro.
(find_pot): Don't test HAVE_DIR.
