executor: pre-allocate memory for slices (#5071)
executor: pre-allocate memory for slices (#5071)


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