Run basic take() test with and without the sum to allow testing preallocated output.

theano/tensor/tests/test_basic.py

@@ -7061,6 +7061,9 @@ class TestTensorInstanceMethods(unittest.TestCase):
         X, _ = self.vars
         x, _ = self.vals
         indices = [1,0,3]
+        assert_array_equal(X.take(indices).eval({X: x}), x.take(indices))
+        # The following line will exercise c_code with non-NULL output_name array
+        # when check_preallocated_output=ALL flag is set. (There should be a better way.)
         assert_array_equal(X.take(indices).sum().eval({X: x}), x.take(indices).sum())
         indices = [1,0,1]
         assert_array_equal(X.take(indices, 1).eval({X: x}), x.take(indices, 1))