dev-db/etcd: Fix etcd2 on arm64

If we build a program, we probably expect to be able to run it.

sdk_container/src/third_party/coreos-overlay/dev-db/etcd/etcd-9999.ebuild

@@ -27,6 +27,11 @@ IUSE="+etcdctl"
 RDEPEND="!dev-db/etcd:0
 	etcdctl? ( !dev-db/etcdctl )"
 
+src_prepare() {
+	epatch "${FILESDIR}/${PN}-2.3.8-fix-pointless-breakage.patch"
+	coreos-go_src_prepare "$@"
+}
+
 src_compile() {
 	GO_LDFLAGS="-X ${COREOS_GO_PACKAGE}/version.GitSHA=${CROS_WORKON_COMMIT:0:7}"
 	go_build "${COREOS_GO_PACKAGE}"

sdk_container/src/third_party/coreos-overlay/dev-db/etcd/files/etcd-2.3.8-fix-pointless-breakage.patch

@@ -0,0 +1,10 @@
+--- etcdmain/etcd.go
++++ etcdmain/etcd.go
+@@ -555,6 +555,7 @@
+ }
+ 
+ func checkSupportArch() {
++	return
+ 	// TODO qualify arm64
+ 	if runtime.GOARCH == "amd64" {
+ 		return