executor: refactor the way to compare rows in MergeJoinExec (#5640)
executor: refactor the way to compare rows in MergeJoinExec (#5640)


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