[Bug other/104431] Provide better error message when GCC "multilib" is missing

[eyalroz1 at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104431

--- Comment #2 from Eyal Rozenberg <eyalroz1 at gmx dot com> ---
(In reply to Andrew Pinski from comment #1)
> How did configure GCC?

I used:

./configure --disable-gnat --disable-fortran

(although I'm not sure --disable-fortran does anything).