dashboard: add builder with optimizations and inlining disabled

LGTM=josharian
R=josharian
CC=golang-codereviews
https://golang.org/cl/148060043

dashboard/coordinator/main.go

@@ -72,6 +72,7 @@ func main() {
 	addBuilder(buildConfig{name: "linux-386-387", env: []string{"GO386=387"}})
 	addBuilder(buildConfig{name: "linux-amd64"})
 	addBuilder(buildConfig{name: "linux-amd64-nocgo", env: []string{"CGO_ENABLED=0", "USER=root"}})
+	addBuilder(buildConfig{name: "linux-amd64-noopt", env: []string{"GO_GCFLAGS=-N -l"}})
 	addBuilder(buildConfig{name: "linux-amd64-race"})
 	addBuilder(buildConfig{name: "nacl-386"})
 	addBuilder(buildConfig{name: "nacl-amd64p32"})