[Bug target/103421] -march=bogus12323123423452345 -march=skylake-avx512 is accepted as a command line option

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103421

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Only the last march is passed down to cc1 which does the verification of the
option :).