allow alien.strings:alien>string to take an object with underlying>> slot

core/alien/strings/strings.factor

@@ -12,6 +12,9 @@ M: c-ptr alien>string
     [ <memory-stream> ] [ <decoder> ] bi*
     "\0" swap stream-read-until drop ;
 
+M: object alien>string
+    [ underlying>> ] dip alien>string ;
+
 M: f alien>string
     drop ;