Created by: DannyIsFunny

【Issue】 ProgramDesc will not be used again after model is loaded, but currently a copy of programDesc in LightPredictor will not be released, which is a waste of memory usage. 【Effect of Current PR】 Remove ProgramDesc data after RuntimeProgram has been built. 【Experiment】 v45 model, 1.1 M. We record the memory usage in Predictor->Run() Effect: A reduce of 200K in memory usage