[Bug other/118223] Improve autodependency generation to avoid full product build

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118223

--- Comment #9 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
-MP option has been around since at least GCC 3.0 even:
https://gcc.gnu.org/onlinedocs/gcc-3.0.4/gcc_3.html#IDX369