optimizer: only create public result fields for table.
optimizer: only create public result fields for table.

Fix `make ddl_test`.

anywhy/tidb,ngaut/tidb,mccxj/tidb,pingcap/tidb,zimulala/tidb,JinheLin/tidb,qiuyesuifeng/tidb,ming-relax/tidb,ming-relax/tidb,zs634134578/tidb,myrice/tidb,spongedu/tidb,c4pt0r/tidb,EvilMcJerkface/tidb,ngaut/tidb,Cofyc/tidb,louishust/tidb,silenceper/tidb,ueizhou/tidb,pingcap/tidb,silenceper/tidb,yangwenmai/tidb,pingcap/tidb,8cbx/tidb,XuHuaiyu/tidb,CodeRushing/tidb,ngaut/tidb,mccxj/tidb,spongedu/tidb,yuanwhy/tidb,kyle-wang/tidb,kyle-wang/tidb,ngaut/tidb,kyle-wang/tidb,XuHuaiyu/tidb,astaxie/tidb,gaocegege/tidb,astaxie/tidb,coocood/tidb,CodeRushing/tidb,c4pt0r/tidb,kyle-wang/tidb,zs634134578/tidb,coocood/tidb,tiancaiamao/tidb,zimulala/tidb,anywhy/tidb,pingcap/tidb,ngaut/tidb,c4pt0r/tidb,silentred/tidb,yangwenmai/tidb,gaocegege/tidb,tiancaiamao/tidb,pingcap/tidb,ngaut/tidb,myrice/tidb,qiuyesuifeng/tidb,pingcap/tidb,simon-xia/tidb,yuanwhy/tidb,c4pt0r/tidb,cosmtrek/tidb,qhsong/tidb,andelf/tidb,simon-xia/tidb,silentred/tidb,wusphinx/tidb,JinheLin/tidb,cosmtrek/tidb,EvilMcJerkface/tidb,kyle-wang/tidb,ueizhou/tidb,wusphinx/tidb,qhsong/tidb,Nify/tidb,c4pt0r/tidb,kyle-wang/tidb,louishust/tidb,Nify/tidb,liyu4/tidb,8cbx/tidb,liyu4/tidb,Cofyc/tidb,andelf/tidb,c4pt0r/tidb