[PATCH] get rid of some TYPE_ARG_TYPES usage by introducing nth_arg_type

[Tobias Burnus]

On Mon 23 May 2011, Nathan Froyd wrote:
> Various places in the compiler grab TYPE_ARG_TYPES and grovel through it
> when what they're really trying to do is index into the list of argument
> types.  The patch below introduces nth_arg_type for such situatiosn and
> changes a hodgepodge of places to use it.  You could, of course, use
> function_args_iterator, but I think this approach is somewhat clearer.
> 
> Tested on x86_64-unknown-linux-gnu.  OK to commit?

> gcc/fortran/
>	* trans-decl.c (create_main_function): Call nth_arg_type.

The Fortran part is OK.

Thanks for the cleanup!

Tobias