message: hack tag_magic to map "OS/2" to "OS2".
diff: :- module ddl.
  -% Copyright (C) 2014-2015 YesLogic Pty. Ltd.
  +% Copyright (C) 2014-2015, 2017 YesLogic Pty. Ltd.
  % All rights reserved.
  :- interface.
  @@ -204,7 +204,12 @@ tag_num_to_string(N) = Tag :-
  char.from_int(B2, C2),
  char.from_int(B3, C3)
  then
  - Tag = string.from_char_list([C0,C1,C2,C3])
  + Tag0 = string.from_char_list([C0,C1,C2,C3]),
  + ( if Tag0 = "OS/2" then
  + Tag = "OS2"
  + else
  + Tag = Tag0
  + )
  else
  abort("not a tag: "++int_to_string(N))
  ).
  