[Bug bootstrap/78616] [7 regression] bootstrap fails for x86_64-darwin at stage1 after 243030 when the bootstrap compiler doesn't have strndup

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78616

--- Comment #10 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
Build breakage should have been fixed as of r243207 (sorry again).

Should we poision strndup in system.h?