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, 0 deletions

diff --git a/eval.c b/eval.c
index 74dc4bf1..be559e6f 100644
--- a/eval.c
+++ b/eval.c
@@ -6771,6 +6771,7 @@ void eval_init(void)
   reg_fun(intern(lit("typeof"), user_package), func_n1(typeof));
   reg_fun(intern(lit("subtypep"), user_package), func_n2(subtypep));
   reg_fun(intern(lit("typep"), user_package), func_n2(typep));
+  reg_fun(intern(lit("built-in-type-p"), user_package), func_n1(built_in_type_p));
 
   reg_fun(intern(lit("atom"), user_package), func_n1(atom));
   reg_fun(intern(lit("null"), user_package), null_f);