[Bug driver/83971] gcc -static link command hardcoded when --with-system-libunwind used

[jason.duerstock at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83971

--- Comment #2 from Jason Duerstock <jason.duerstock at gmail dot com> ---
At least tangentially related, what's the reason only ia64 needs libunwind? 
What happens if gcc is built with --disable-libunwind-exceptions?  I haven't
been able to find a clear explanation regarding this anywhere.