[lto] tree.c: Introduce stdarg_p.

[Ian Lance Taylor]

Kazu Hirata <kazu@codesourcery.com> writes:

> 2006-06-09  Kazu Hirata  <kazu@codesourcery.com>
> 
> 	* tree.c (stdarg_p): New.
> 	* tree.h: Add a prototype for stdarg_p.
> 	* builtins.c (fold_builtin_next_arg): Call stdarg_p.
> 	* config/i386/i386.c (ix86_return_pops_args,
> 	ix86_setup_incoming_varargs): Likewise.
> 	* dwarf2out.c (gen_subprogram_die): Likewise.
> 	* function.c (allocate_struct_function): Likewise.

This is OK, but please change this comment:

> +/* Return true if function type FNTYPE is a stdarg.  */

to something more like "Return whether function type FNTYPE was
declared with an ellipsis (e.g., uses <stdarg.h>)."  Only maybe
better.  I think we can be slightly more descriptive than "a stdarg."

Thanks.

Ian