Windows: chrootarchive refactor

Signed-off-by: John Howard <jhoward@microsoft.com>

chrootarchive/archive_unix.go

@@ -0,0 +1,14 @@
+// +build !windows
+
+package chrootarchive
+
+import (
+	"syscall"
+)
+
+func chroot(path string) error {
+	if err := syscall.Chroot(path); err != nil {
+		return err
+	}
+	return syscall.Chdir("/")
+}