cmd/mbf: keep non-native entries alive

Signed-off-by: Ophestra <cat@gensokyo.uk>

cmd/mbf/main.go

@@ -782,11 +782,20 @@ func main() {
 			"Remove identifiers not reachable by loaded packages",
 			func([]string) error {
 				return cm.Do(func(cache *pkg.Cache) error {
-					t := rosa.Native().Std()
+					t := rosa.Native().Clone().Std()
+					a := t.Append(nil, t.CollectAll()...)
+					for arch := range pkg.Arch() {
+						if arch == runtime.GOARCH {
+							continue
+						}
+						t.DropCaches(arch, t.Flags())
+						a = t.Append(a, t.CollectAll()...)
+					}
+
 					ids, checksums, err := cache.Clean(
 						flagDry,
 						!flagDeep,
-						t.Append(nil, t.CollectAll()...)...,
+						a...,
 					)
 					log.Printf(
 						"destroyed %d identifier and %d checksum entries",