go.crypto/ssh: add benchmarks for marshal and unmarshal
go.crypto/ssh: add benchmarks for marshal and unmarshal

R=agl
CC=golang-dev
https://golang.org/cl/5730045

cmars/tools,Carrotman42/crypto,cheffo/crypto,tca/crypto,CodyGuo/crypto,kim-racktop/crypto,ScriptRock/crypto,golang/crypto,cmars/tools,conseweb/golangcrypto,golang/crypto,bford/golang-x-crypto,golang/crypto,pki-io/crypto,progrium/crypto,cheffo/crypto,mattharden/crypto,thomaso-mirodin/crypto,juniorz/crypto,cmars/tools,a-palchikov/crypto,thomaso-mirodin/crypto,ScriptRock/crypto,bford/golang-x-crypto,CodyGuo/crypto,zj8487/crypto,a-palchikov/crypto,wooutl/golangcrypto,conseweb/golangcrypto,tca/crypto,lucevers/crypto,mattharden/crypto,guaiguaihw/crypto,zj8487/crypto,cmars/tools,kim-racktop/crypto,progrium/crypto,guaiguaihw/crypto,pki-io/crypto,lucevers/crypto,wooutl/golangcrypto,juniorz/crypto,Carrotman42/crypto