[Patch, Fortran] PR39505 - add support for !GCC$ attributes NO_ARG_CHECK

[Thomas Koenig]

Hi Tobias,

> Minor patch update due to Janus' gfc_explicit_interface_required patch.
>
> Build and regtested on x86-64-gnu-linux.
> OK for the trunk?

I see that it can be useful, but I really dislike disabling the TKR
checks.

Can you put this behind an option so the user has to specify that
he really means it?

OK with this change; also OK if other people think that requiring
such an option is a Bad Idea.

	Thomas