Fix issue which cause abnormal CPU usage in stack op
Fix issue which cause abnormal CPU usage in stack op

Stack OP has much higher CPU cost than expected in release mode.
Caused by DebugStringEx() in base class OperatorWithKernel. Actually
this issue occur for each OP which hasn't implement it's own
GetExpectedKernelType().

test=develop

PaddlePaddle/Paddle,baidu/Paddle,baidu/Paddle,baidu/Paddle,chengduoZH/Paddle,luotao1/Paddle,tensor-tang/Paddle,tensor-tang/Paddle,luotao1/Paddle,PaddlePaddle/Paddle,PaddlePaddle/Paddle,luotao1/Paddle,PaddlePaddle/Paddle,luotao1/Paddle,chengduoZH/Paddle,baidu/Paddle,luotao1/Paddle,tensor-tang/Paddle,baidu/Paddle,tensor-tang/Paddle,chengduoZH/Paddle,luotao1/Paddle,PaddlePaddle/Paddle,luotao1/Paddle,PaddlePaddle/Paddle,PaddlePaddle/Paddle,tensor-tang/Paddle,chengduoZH/Paddle,chengduoZH/Paddle