expression: improve baseBuiltinFunc.evalTime and evalDuration (#3437)
expression: improve baseBuiltinFunc.evalTime and evalDuration (#3437)


c4pt0r/tidb,ngaut/tidb,ming-relax/tidb,8cbx/tidb,ngaut/tidb,Nify/tidb,mccxj/tidb,Cofyc/tidb,coocood/tidb,qiuyesuifeng/tidb,c4pt0r/tidb,ngaut/tidb,pingcap/tidb,zs634134578/tidb,Nify/tidb,kyle-wang/tidb,c4pt0r/tidb,XuHuaiyu/tidb,ngaut/tidb,EvilMcJerkface/tidb,gaocegege/tidb,EvilMcJerkface/tidb,pingcap/tidb,kyle-wang/tidb,CodeRushing/tidb,zs634134578/tidb,louishust/tidb,yuanwhy/tidb,tiancaiamao/tidb,kyle-wang/tidb,wusphinx/tidb,yangwenmai/tidb,8cbx/tidb,spongedu/tidb,kyle-wang/tidb,c4pt0r/tidb,cosmtrek/tidb,c4pt0r/tidb,ngaut/tidb,pingcap/tidb,cosmtrek/tidb,CodeRushing/tidb,kyle-wang/tidb,qiuyesuifeng/tidb,yuanwhy/tidb,mccxj/tidb,c4pt0r/tidb,gaocegege/tidb,ming-relax/tidb,coocood/tidb,kyle-wang/tidb,louishust/tidb,pingcap/tidb,pingcap/tidb,yangwenmai/tidb,zimulala/tidb,tiancaiamao/tidb,Cofyc/tidb,zimulala/tidb,pingcap/tidb,spongedu/tidb,wusphinx/tidb,XuHuaiyu/tidb,ngaut/tidb