executor: fix panic on Stream Aggregate (#6984)
executor: fix panic on Stream Aggregate (#6984)


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