release/dist/synology: build hi3535 as armv5, not armv7

This platform is technically an armv7, but has no hardware floating
point unit. armv5 is the only target Go understands to lack floating
point, so use that.

Updates #6860

Signed-off-by: David Anderson <danderson@tailscale.com>

release/dist/synology/targets.go

@@ -5,6 +5,27 @@ package synology
 
 import "tailscale.com/release/dist"
 
+var v5Models = []string{
+	"armv5",
+	"88f6281",
+	"88f6282",
+	// hi3535 is actually an armv7 under the hood, but with no
+	// hardware floating point. To the Go compiler, that means it's an
+	// armv5.
+	"hi3535",
+}
+
+var v7Models = []string{
+	"armv7",
+	"alpine",
+	"armada370",
+	"armada375",
+	"armada38x",
+	"armadaxp",
+	"comcerto2k",
+	"monaco",
+}
+
 func Targets(forPackageCenter bool) []dist.Target {
 	var ret []dist.Target
 	for _, dsmVersion := range []int{6, 7} {
@@ -40,7 +61,7 @@ func Targets(forPackageCenter bool) []dist.Target {
 		// On older ARMv5 and ARMv7 platforms, synology used a whole
 		// mess of SoC-specific target names, even though the packages
 		// built for each are identical apart from metadata.
-		for _, v5Arch := range []string{"armv5", "88f6281", "88f6282"} {
+		for _, v5Arch := range v5Models {
 			ret = append(ret, &target{
 				filenameArch:    v5Arch,
 				dsmMajorVersion: dsmVersion,
@@ -52,7 +73,7 @@ func Targets(forPackageCenter bool) []dist.Target {
 				packageCenter: forPackageCenter,
 			})
 		}
-		for _, v7Arch := range []string{"armv7", "alpine", "armada370", "armada375", "armada38x", "armadaxp", "comcerto2k", "monaco", "hi3535"} {
+		for _, v7Arch := range v7Models {
 			ret = append(ret, &target{
 				filenameArch:    v7Arch,
 				dsmMajorVersion: dsmVersion,