Remove old code, the cache was removed from the CPU op, but not the GPU op.

theano/sandbox/gpuarray/subtensor.py

@@ -31,15 +31,10 @@ class GpuSubtensor(HideC, Subtensor):
     def perform(self, node, inputs, out_):
         out, = out_
         x = inputs[0]
-        if self.perform_cache_cdata is not None:
-            out[0] = x.__getitem__(self.perform_cache_cdata)
-            return
 
         cdata = get_idx_list(inputs, self.idx_list)
         if len(cdata) == 1:
             cdata = cdata[0]
-        if len(inputs) == 1:
-            self.perform_cache_cdata = cdata
 
         out[0] = x.__getitem__(cdata)