for review: add nested modules [4/5]

[Simon Taylor]

In type_util.m
>@@ -375,14 +376,11 @@
> 
> type_is_no_tag_type(Ctors, Ctor, Type) :-
> 	Ctors = [Ctor - [_FieldName - Type]],
>-	Ctor \= qualified("mercury_builtin", "type_info"),
>-	Ctor \= qualified("mercury_builtin", "base_type_info"),
>-	Ctor \= unqualified("type_info"),
>-	Ctor \= unqualified("base_type_info"),
>-	Ctor \= qualified("mercury_builtin", "typeclass_info"),
>-	Ctor \= qualified("mercury_builtin", "base_typeclass_info"),
>-	Ctor \= unqualified("typeclass_info"),
>-	Ctor \= unqualified("base_typeclass_info").
>+	unqualify_name(Ctor, Name),
>+	Name \= "type_info",
>+	Name \= "base_type_info",
>+	Name \= "typeclass_info",
>+	Name \= "base_typeclass_info".

You should probably check for the mercury_private_builtin_module part here.
All occurrences of the type_info, base_type_info and base_typeclass_info
constructors should be module qualified.