message: let StridedSlice layer support const input
diff: @@ -1706,6 +1706,19 @@ void TFImporter::parseStridedSlice(tensorflow::GraphDef& net, const tensorflow::
  layerParams.set("begin", DictValue::arrayInt((int*)begins.data, begins.total()));
  layerParams.set("end", DictValue::arrayInt((int*)ends.data, ends.total()));
  + Pin inp = parsePin(layer.input(0));
  + if (value_id.find(inp.name) != value_id.end())
  + {
  + // The input is constant.
  + LayerParams lp;
  + lp.name = inp.name;
  + lp.type = "Const";
  + lp.blobs.push_back(getTensorContent(getConstBlob(layer, value_id, 0)));
  +
  + int constInpId = dstNet.addLayer(lp.name, lp.type, lp);
  + layer_id[lp.name] = constInpId;
  + }
  +
  int id = dstNet.addLayer(name, "Slice", layerParams);
  layer_id[name] = id;
  