[Bug other/64534] New: invalid -march value incosistency

["jlec at gentoo dot org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64534

            Bug ID: 64534
           Summary: invalid -march value incosistency
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: other
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jlec at gentoo dot org

Overwriting invalid -march later in the command line has an inconsistency

Following works

gcc -march=no-automagic -march=core2
gcc -march=no-automagic -march=pentium-m

Following breaks

gcc -march=no-automagic -march=native


I would prefer that the build always breaks with 

error: bad value (no-automagic) for -march= switch

but we should at least have the same behavior for both cases.