[PATCH] Fortran: improve checking of character length specification [PR96025]

[Thomas Koenig]

Hi Harald,

> the attached patch fixes an ICE on invalid (non-integer)
> specification expressions for character length in function
> declarations.  It appears that the error handling was
> already in place (mostly) and we need to essentially
> prevent run-on errors.
> 
> Regtested on x86_64-pc-linux-gnu.  OK for mainline?
As a very minor matter of style, you might want to write

           function_result_typed = check_function_result_typed ();

instead of

	  if (check_function_result_typed ())
	    function_result_typed = true;

OK either way.

> The PR is marked as a 10/11/12/13 regression, so I would
> like to backport this as far as it seems reasonable.

Also OK.

Thanks for the patch!

Best regards

	Thomas