Add __eq__ and __hash__ to GpuAlloc.

theano/sandbox/gpuarray/basic_ops.py

@@ -437,10 +437,15 @@ cuda_from_gpu = CudaFromGpu()
 
 
 class GpuAlloc(Op):
-
     def __str__(self):
         return 'GpuAlloc'
 
+    def __hash__(self):
+        return hash(type(self))
+
+    def __eq__(self, other):
+        return type(self) == type(other)
+
     def make_node(self, value, *shape):
         v = as_gpuarray_variable(value)
         sh = [tensor.as_tensor_variable(s) for s in shape]