[Bug sanitizer/78267] [7 Regression] libsanitizer breaks bootstrap on x86_64-apple-darwin16 at r241977

[m.ostapenko at samsung dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78267

--- Comment #28 from Maxim Ostapenko <m.ostapenko at samsung dot com> ---
So, perhaps I can commit it (from #15) as Jakub suggested to restore GCC
bootstrap for now?