TestExpressions.test_where fails on sparc
```
======================================================================
FAIL: test_where (pandas.tests.test_expressions.TestExpressions)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/«BUILDDIR»/pandas-0.15.1+git125-ge463818/debian/tmp/usr/lib/python2.7/dist-packages/pandas/tests/test_expressions.py", line 341, in test_where
    testit()
  File "/«BUILDDIR»/pandas-0.15.1+git125-ge463818/debian/tmp/usr/lib/python2.7/dist-packages/pandas/tests/test_expressions.py", line 333, in testit
    assert_array_equal(result,expected)
  File "/usr/lib/python2.7/dist-packages/numpy/testing/utils.py", line 718, in assert_array_equal
    verbose=verbose, header='Arrays are not equal')
  File "/usr/lib/python2.7/dist-packages/numpy/testing/utils.py", line 644, in assert_array_compare
    raise AssertionError(msg)
AssertionError: 
Arrays are not equal

(mismatch 5.235%)
 x: array([[-0.46795435, -1.35639322,  0.        ,  0.        ],
       [-0.03855877, -1.09147549,  0.        , -2.        ],
       [ 1.10923046, -0.46480593,  1.        ,  0.        ],...
 y: array([[-0.46795435, -1.35639322,  0.        ,  0.        ],
       [-0.03855877, -1.09147549,  0.        , -2.        ],
       [ 1.10923046, -0.46480593,  1.        ,  0.        ],...
```

interestingly doesn't fail on s390x or powerpc so not strictly a BE problem
see https://buildd.debian.org/status/fetch.php?pkg=pandas&arch=sparc&ver=0.15.1%2Bgit125-ge463818-1&stamp=1417703234 for more info
