refactor: Move File and FileInfo to pkg

pkg/fs/stat_unix.go

@@ -0,0 +1,23 @@
+//go:build linux
+
+package fs
+
+import "syscall"
+
+type Stat syscall.Stat_t
+
+func NewStat(
+	uid uint32,
+	gid uint32,
+	mtim int64,
+	atim int64,
+	ctim int64,
+) *Stat {
+	return &Stat{
+		Uid:  uid,
+		Gid:  gid,
+		Mtim: syscall.NsecToTimespec(mtim),
+		Atim: syscall.NsecToTimespec(atim),
+		Ctim: syscall.NsecToTimespec(ctim),
+	}
+}