net: return rooted DNS names on Plan 9
net: return rooted DNS names on Plan 9

This change returns rooted DNS names on Plan 9,
for consistency with other operating systems.

Updates #12193.

Change-Id: If983920c5b9a8f67d4ccb51bb295fac8dfb87e88
Reviewed-on: https://go-review.googlesource.com/15581
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>
Run-TryBot: David du Colombier <ec8ae1e6620d4bab5e0e7aa2a6ae41aad63e3708@gmail.com>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Mikio Hara <e2f4d2eec1d9a1f781345cdd7260d7d52e6468ae@gmail.com>

polyverse-security/go,kim-racktop/go,josharian/go,4ad/go,deft-code/go,cyberroadie/go,Samurais/go,vanloswang/go,codestation/go,CAFxX/go,goodlang/good,roth1002/go,akutz/go,fjballest/golang,sndnvaps/go,ganboing/go-esx,deft-code/go,polyverse-security/go,goodlang/good,golang/go,kim-racktop/go,goodlang/good,roth1002/go,vsekhar/elastic-go,4ad/go,polyverse-security/go,odeke-em/go,Endika/go,nawawi/go,codestation/go,linux-on-ibm-z/go,cyberroadie/go,CAFxX/go,Endika/go,vanloswang/go,4ad/go,theif519/go,odeke-em/go,Endika/go,sndnvaps/go,ganboing/go-esx,Cofyc/go,derekmarcotte/go,odeke-em/go,mwhudson/go,binarycrusader/go,4ad/go,sndnvaps/go,deft-code/go,Samurais/go,Cofyc/go,codestation/go,derekmarcotte/go,suncycheng/go,nawawi/go,roth1002/go,vanloswang/go,mwhudson/go,ImJasonH/go,Samurais/go,deft-code/go,golang/go,cyberroadie/go,theif519/go,golang/go,linux-on-ibm-z/go,vsekhar/elastic-go,momchil-velikov/go,golang/go,CAFxX/go,cyberroadie/go,CAFxX/go,sndnvaps/go,binarycrusader/go,sndnvaps/go,fjballest/golang,golang/go,theif519/go,golang/go,polyverse-security/go,miolini/go,ImJasonH/go,miolini/go,Samurais/go,theif519/go,kim-racktop/go,binarycrusader/go,odeke-em/go,deft-code/go,josharian/go,linux-on-ibm-z/go,suncycheng/go,roth1002/go,ganboing/go-esx,deft-code/go,vanloswang/go,momchil-velikov/go,miolini/go,mwhudson/go,akutz/go,4ad/go,Samurais/go,odeke-em/go,binarycrusader/go,ganboing/go-esx,momchil-velikov/go,ganboing/go-esx,cyberroadie/go,cloudflare/go,miolini/go,josharian/go,momchil-velikov/go,codestation/go,cyberroadie/go,linux-on-ibm-z/go,josharian/go,momchil-velikov/go,christopher-henderson/Go,theif519/go,fjballest/golang,vsekhar/elastic-go,binarycrusader/go,vsekhar/elastic-go,vanloswang/go,roth1002/go,cyberroadie/go,fjballest/golang,cloudflare/go,cloudflare/go,Cofyc/go,ImJasonH/go,mwhudson/go,josharian/go,Endika/go,polyverse-security/go,roth1002/go,akutz/go,derekmarcotte/go,golang/go,fjballest/golang,miolini/go,vanloswang/go,vanloswang/go,kim-racktop/go,4ad/go,derekmarcotte/go,derekmarcotte/go,derekmarcotte/go,vsekhar/elastic-go,CAFxX/go,ganboing/go-esx,akutz/go,Cofyc/go,Endika/go,akutz/go,Cofyc/go,sndnvaps/go,josharian/go,theif519/go,CAFxX/go,linux-on-ibm-z/go,mwhudson/go,odeke-em/go,sndnvaps/go,Samurais/go,binarycrusader/go,fjballest/golang,momchil-velikov/go,cyberroadie/go,cloudflare/go,goodlang/good,polyverse-security/go,goodlang/good,nawawi/go,momchil-velikov/go,suncycheng/go,theif519/go,codestation/go,ImJasonH/go,odeke-em/go,nawawi/go,miolini/go,akutz/go,kim-racktop/go,vsekhar/elastic-go,Endika/go,CAFxX/go,binarycrusader/go,CAFxX/go,ImJasonH/go,ImJasonH/go,roth1002/go,4ad/go,codestation/go,mwhudson/go,miolini/go,suncycheng/go,vsekhar/elastic-go,Endika/go,Cofyc/go,cloudflare/go,akutz/go,goodlang/good,binarycrusader/go,josharian/go,akutz/go,codestation/go,linux-on-ibm-z/go,Samurais/go,ganboing/go-esx,ganboing/go-esx,fjballest/golang,momchil-velikov/go,fjballest/golang,codestation/go,vsekhar/elastic-go,suncycheng/go,deft-code/go,vanloswang/go,goodlang/good,Endika/go,mwhudson/go,4ad/go,linux-on-ibm-z/go,kim-racktop/go,nawawi/go,kim-racktop/go,derekmarcotte/go,nawawi/go,ImJasonH/go,cloudflare/go,suncycheng/go,nawawi/go,Cofyc/go,polyverse-security/go,odeke-em/go,mwhudson/go,suncycheng/go,goodlang/good,josharian/go,kim-racktop/go,cloudflare/go,sndnvaps/go,theif519/go,nawawi/go,Cofyc/go,roth1002/go,golang/go,cloudflare/go,ImJasonH/go,linux-on-ibm-z/go,Samurais/go,derekmarcotte/go,deft-code/go,suncycheng/go,miolini/go,polyverse-security/go