rust-dirstate: use EntryState enum instead of literals
This improves code readability quite a bit, while also adding a layer of
safety because we're checking the state byte against the enum.
Differential Revision: https://phab.mercurial-scm.org/D6629
#!/usr/bin/env python
from __future__ import absolute_import, print_function
import errno
import os
import sys
for f in sys.argv[1:]:
try:
print(f, '->', os.readlink(f))
except OSError as err:
if err.errno != errno.EINVAL:
raise
print(f, '->', f, 'not a symlink')
sys.exit(0)