[Bug libobjc/64051] broken exception model detection in libobjc's configure

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64051

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
As far as I know a Canadian cross requires the cross toolchain to that target
at least the same languages as the Canadian cross. This check is the same check
in libstdc++ also.