go.tools/go/types: enable another test case
go.tools/go/types: enable another test case

Working now that circular interface types are handled correcly.

R=adonovan
CC=golang-dev
https://golang.org/cl/16310046

argandas/tools,cmars/tools,cw2018/tools,dmitris/tools,nicot/tools,magiccao/tools,syreclabs/go-tools,cw2018/tools,dmitris/tools,maddyonline/tools,argandas/tools,josharian/tools,springning/tools,matryer/tools,runcom/tools,argandas/tools,maddyonline/tools,golang/tools,glasser/golang-tools,springning/tools,runcom/tools,runcom/tools,nicot/tools,golang/tools,golang/tools,jdhenke/tools,cw2018/tools,syreclabs/go-tools,nicot/tools,jdhenke/tools,magiccao/tools,syreclabs/go-tools,josharian/tools,cw2018/tools,matryer/tools,springning/tools,4ad/tools,matryer/tools,golang/tools,golang/tools,4ad/tools,dmitris/tools,syreclabs/go-tools,matryer/tools,sshetty10/tools,syreclabs/go-tools,magiccao/tools,cmars/tools,magiccao/tools,jdhenke/tools,4ad/tools,maddyonline/tools,glasser/golang-tools,sshetty10/tools,nicot/tools,cmars/tools,syreclabs/go-tools,glasser/golang-tools,argandas/tools,josharian/tools,maddyonline/tools,jdhenke/tools,glasser/golang-tools,sshetty10/tools,cmars/tools,sshetty10/tools,josharian/tools,dmitris/tools,runcom/tools,springning/tools