executor: some move some function position about index lookup reader (#5910)
executor: some move some function position about index lookup reader (#5910)


cosmtrek/tidb,wusphinx/tidb,kyle-wang/tidb,kyle-wang/tidb,c4pt0r/tidb,ngaut/tidb,pingcap/tidb,ngaut/tidb,c4pt0r/tidb,qiuyesuifeng/tidb,qiuyesuifeng/tidb,ngaut/tidb,EvilMcJerkface/tidb,coocood/tidb,ming-relax/tidb,pingcap/tidb,ngaut/tidb,Cofyc/tidb,XuHuaiyu/tidb,kyle-wang/tidb,yangwenmai/tidb,XuHuaiyu/tidb,pingcap/tidb,kyle-wang/tidb,EvilMcJerkface/tidb,tiancaiamao/tidb,c4pt0r/tidb,wusphinx/tidb,pingcap/tidb,c4pt0r/tidb,ngaut/tidb,CodeRushing/tidb,coocood/tidb,pingcap/tidb,ngaut/tidb,ming-relax/tidb,CodeRushing/tidb,kyle-wang/tidb,Nify/tidb,mccxj/tidb,Nify/tidb,mccxj/tidb,cosmtrek/tidb,Cofyc/tidb,pingcap/tidb,yangwenmai/tidb,kyle-wang/tidb,c4pt0r/tidb,tiancaiamao/tidb,c4pt0r/tidb