[patch, fortran] Fix PR 87689, wrong decls / ABI violation on POWER

[Thomas Koenig]

Hi Janne,

> I'm not really sure if there is any good reason why GFortran occasionally
> generates these varargs declarations, hence my suggestion to get rid of
> them. Unless the middle-end is planning to get rid of untyped function
> decls?

Are they still being generated after the patch went in?  I'm not sure,
but because I wanted to change as little as possible, I did not try
to change that aspect of the code.

Regards

	Thomas