godoc: add forgotten file from last CL to fix build
godoc: add forgotten file from last CL to fix build

R=adg, franciscossouza, dave
CC=golang-dev
https://golang.org/cl/25650043

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