Failed debugging output of incomplete range

Compilation of regular expression with incomplete range is successed, but is 
failed with regex.DEBUG.

>>> import regex
>>> regex.compile('[a-]')
regex.Regex('[a-]', flags=regex.V0)
>>> regex.compile('[a-]', regex.DEBUG)
SET_UNION MATCH
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/serhiy/py/cpython/Lib/regex.py", line 331, in compile
    return _compile(pattern, flags, kwargs)
  File "/home/serhiy/py/cpython/Lib/regex.py", line 508, in _compile
    parsed.dump(indent=0, reverse=reverse)
  File "/home/serhiy/py/cpython/Lib/_regex_core.py", line 1705, in dump
    self._dump(indent, reverse)
  File "/home/serhiy/py/cpython/Lib/_regex_core.py", line 3198, in _dump
    i.dump(indent + 1)
TypeError: dump() missing 1 required positional argument: 'reverse'

Original issue reported on code.google.com by storch...@gmail.com on 8 Oct 2014 at 8:38

Merged into: #121

Forever-Young / mrab-regex-hg

Failed debugging output of incomplete range #122