cmd/compile: remove unused (dead) fields
cmd/compile: remove unused (dead) fields

Change-Id: I4816a788e7b89b76dc70d05f4b176e99684d0680
Reviewed-on: https://go-review.googlesource.com/18830
Run-TryBot: Robert Griesemer <a6752097faebf1f02d80107d77a9be009089afe3@golang.org>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Brad Fitzpatrick <ae9783c0b0efc69cd85ab025ddd17aa44cdc4aa5@golang.org>

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