MultiIndex.reindex(Int64Index) -> unhelpful Cython error
```

test_crosstab_margins (__main__.TestCrosstab) ... > /home/wesm/code/pandas/generated.pyx(132)pandas._tseries.merge_indexer_object (pandas/src/tseries.c:28324)()
(Pdb) u
> /home/wesm/code/pandas/pandas/core/index.py(1548)get_indexer()
-> indexer = self._merge_indexer(target_index, self_index.indexMap)
(Pdb) target_index
Int64Index([  4,   4,   1,   2,   4,   3,   7,   5,   4,   3,   1,   1,   0,
         6,   5,   2,   2,   3,   2,   5,   5,   1,   4,   3,   5,   4,
         4,   3,   4,   3, 100])
(Pdb) self
MultiIndex([(0, 0), (0, 1), (0, 2), (0, 3), (0, 4), (0, 5), (0, 6), (0, 7),
       (0, 8), (0, 9), (1, 0), (1, 1), (1, 3), (1, 4), (1, 5), (1, 6),
       (1, 7), (1, 8), (1, 9), (2, 0), (2, 1), (2, 2), (2, 3), (2, 4),
       (2, 5), (2, 6), (2, 7), (2, 8), (2, 9), ('All', '')], dtype=object)
(Pdb) c
ERROR

======================================================================
ERROR: test_crosstab_margins (__main__.TestCrosstab)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "pandas/tools/tests/test_pivot.py", line 201, in test_crosstab_margins
    exp_rows = exp_rows.reindex(all_rows).fillna(0)
  File "/home/wesm/code/pandas/pandas/core/series.py", line 1585, in reindex
    level=level)
  File "/home/wesm/code/pandas/pandas/core/index.py", line 1569, in reindex
    indexer = self.get_indexer(target, method=method)
  File "/home/wesm/code/pandas/pandas/core/index.py", line 1548, in get_indexer
    indexer = self._merge_indexer(target_index, self_index.indexMap)
  File "generated.pyx", line 132, in pandas._tseries.merge_indexer_object (pandas/src/tseries.c:28324)
ValueError: Buffer dtype mismatch, expected 'Python object' but got 'long'

----------------------------------------------------------------------
```
