COMPAT: 32-bit build failures

[jreback]

started happening on dec 12-13 on 32-bit for 2.7/3.5
https://travis-ci.org/MacPython/pandas-wheels/jobs/316191146

________________ TestConcatenate.test_concat_tz_series_tzlocal _________________
self = <pandas.tests.reshape.test_concat.TestConcatenate object at 0xe28a96cc>
    def test_concat_tz_series_tzlocal(self):
        # see gh-13583
        x = [pd.Timestamp('2011-01-01', tz=dateutil.tz.tzlocal()),
             pd.Timestamp('2011-02-01', tz=dateutil.tz.tzlocal())]
        y = [pd.Timestamp('2012-01-01', tz=dateutil.tz.tzlocal()),
             pd.Timestamp('2012-02-01', tz=dateutil.tz.tzlocal())]
    
        result = concat([pd.Series(x), pd.Series(y)], ignore_index=True)
        tm.assert_series_equal(result, pd.Series(x + y))
>       assert result.dtype == 'datetime64[ns, tzlocal()]'
E       TypeError: Invalid datetime unit in metadata string "[ns, tzlocal()]"
/venv/lib/python3.6/site-packages/pandas/tests/reshape/test_concat.py:1796: TypeError
----------------------------- Captured stderr call -----------------------------
OverflowError: Python int too large to convert to C ssize_t
Exception ignored in: 'pandas._libs.tslibs.conversion._localize_tso'
OverflowError: Python int too large to convert to C ssize_t
OverflowError: Python int too large to convert to C ssize_t
Exception ignored in: 'pandas._libs.tslibs.conversion._localize_tso'
OverflowError: Python int too large to convert to C ssize_t
OverflowError: Python int too large to convert to C ssize_t
Exception ignored in: 'pandas._libs.tslibs.conversion._localize_tso'
OverflowError: Python int too large to convert to C ssize_t
OverflowError: Python int too large to convert to C ssize_t
Exception ignored in: 'pandas._libs.tslibs.conversion._localize_tso'
OverflowError: Python int too large to convert to C ssize_t
 1 failed, 16040 passed, 2464 skipped, 74 xfailed, 1 xpassed in 464.80 seconds =

[jreback]

cc @jschendel
cc @jbrockmendel

its possible the astype fixes triggered this, but the bug existed previously