[fortran,patch] Forbid assignment of different character kinds

[FX]

> In the test case, could you also add a "PR fortran/36534" to the
> as comment?

Sure.


> Additionally, I wonder whether instead of the name-based checking
> +	  && (sym->name[0] != '_' || sym->name[1] != '_'))
> it wouldn't be cleaner to check
>          && sym->attr.intrinsic
> (If you change it to attr.intrinsic, you need to set
> the attribute also in intrinsic.c's gfc_convert_type_warn.)
> 
> I know that using __... names it not really possible in Fortran (except as C
> binding name), but - still - I think it is cleaner. But I am fine with
> either version.

OK, it sounds logical, so I tried that… it gets caught later in resolve.c, saying “… declared INTRINSIC at %L does not exist”, because it’s not actually a proper intrinsic, it’s just a function call manually constructed.

In the interest of minimal modification of this code, I have committed the original approach as rev. 215887.

Thanks for the review.
FX