go: Correctly build (cross-)compilers

Without passing the --no-clean flag to make.bash, each build will
overwrite the previous one. This means that we always ended up with a
single compiler, that for x86_64.

srcpkgs/go/template

@@ -32,17 +32,15 @@ do_build() {
 	export GOOS=linux
 
 	cd src
-	# ARM build
-	export GOARCH=arm
-	bash make.bash
 
-	# x86 build
-	export GOARCH=386
-	bash make.bash
+	# TODO We could very well also build windows and darwin
+	# cross-compilers here, at no added complexity
 
-	# x86_64 build
-	export GOARCH=amd64
-	bash make.bash
+	# Build ARM, x86 and x86_64 compilers
+	for arch in arm 386 amd64; do
+		export GOARCH=$arch
+		bash make.bash --no-clean
+	done
 }
 
 do_install() {