defstruct: diagnose built-in type being redefined.

* eval.c (eval_init): Register built-in-type-p intrinsic.

* lib.c (buitin_type_p): Rename to built_in_type_p since the
word built-in is hyphenated. The function also tests
whether the argument is a COBJ class.
(cobj_class_exists): Function removed.

* stdlib/doc-syms.tl: Updated.

* stdlib/struct.tl (defstruct): Add built-in-type-p check.

* struct.c (make_struct_type): Call only built_in_type_p;
cobj_class_exists is gone.

* txr.1: Document built-in-type-p.

1 files changed, 1 insertions, 1 deletions

diff --git a/struct.c b/struct.c
index aa6b86d1..2f643dae 100644
--- a/struct.c
+++ b/struct.c
@@ -439,7 +439,7 @@ val make_struct_type(val name, val supers,
 
   lisplib_try_load(name);
 
-  if (builtin_type_p(name) || cobj_class_exists(name))
+  if (built_in_type_p(name))
     uw_throwf(error_s, lit("~a: ~s is a built-in type"),
               self, name, nao);