dashboard: set -march=armv6 on linux-arm-aws

This is currently set directly in cmd/release, which means we're not
testing what we're releasing.

With this done, we no longer need special handling in cmd/release.

Updates golang/go#18748.

Change-Id: Ib9bd19a2a07e98f64c0169d5d31976c7c61f656f
Reviewed-on: https://go-review.googlesource.com/c/build/+/390395
Run-TryBot: Heschi Kreinick <heschi@google.com>
Reviewed-by: Carlos Amedee <carlos@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Trust: Heschi Kreinick <heschi@google.com>

cmd/release/release.go

@@ -428,12 +428,6 @@ func (b *Build) make() error {
 		"GOBIN=",
 	)
 
-	if b.Goarm > 0 {
-		env = append(env, fmt.Sprintf("GOARM=%d", b.Goarm))
-		env = append(env, fmt.Sprintf("CGO_CFLAGS=-march=armv%d", b.Goarm))
-		env = append(env, fmt.Sprintf("CGO_LDFLAGS=-march=armv%d", b.Goarm))
-	}
-
 	// Issues #36025 #35459
 	if b.OS == "darwin" && b.Arch == "amd64" {
 		minMacVersion := minSupportedMacOSVersion(*version)

dashboard/builders.go

@@ -2490,6 +2490,8 @@ func init() {
 			"GOARCH=arm",
 			"GOARM=6",
 			"GOHOSTARCH=arm",
+			"CGO_CFLAGS=-march=armv6",
+			"CGO_LDFLAGS=-march=armv6",
 		},
 	})
 	addBuilder(BuildConfig{