Fix problems when it is cudnn v5 that is installed.

theano/gpuarray/cudnn_defs.py

@@ -88,6 +88,9 @@ class CuDNNV51(object):
     cudnnBatchNormMode_t = CEnumType(('CUDNN_BATCHNORM_PER_ACTIVATION', 'per-activation'),
                                      ('CUDNN_BATCHNORM_SPATIAL', 'spatial'),
                                      ctype='cudnnBatchNormMode_t')
+    # It was introduced in cudnnv6, but we need to define it with an
+    # empty list of enum to don't crash with cudnn 5
+    cudnnReduceTensorOp_t = CEnumType()
 
 
 class CuDNNV6(CuDNNV51):

theano/gpuarray/tests/test_dnn.py

@@ -1437,7 +1437,7 @@ def dnn_reduction(nd, idtype, acc_dtype, odtype):
 
 
 def test_dnn_reduction_opt():
-    if not dnn.dnn_available(test_ctx_name):
+    if not dnn.dnn_available(test_ctx_name) or dnn.version(raises=False) < 6000:
         raise SkipTest(dnn.dnn_available.msg)
 
     for nd in range(1, 9):