chunk:  reduce chunk's iterator function call (#7585)
chunk:  reduce chunk's iterator function call (#7585)


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