[Bug testsuite/126923] Additional testsuite failures when configured with --with-arch=native --with-cpu=native

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126923

--- Comment #2 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by H.J. Lu <[email protected]>:

https://gcc.gnu.org/g:1fb18207ae8aa92c2ef1b1878c1c1a87039685be

commit r17-3392-g1fb18207ae8aa92c2ef1b1878c1c1a87039685be
Author: H.J. Lu <[email protected]>
Date:   Tue Aug 18 13:15:30 2026 +0800

    mv28.C: Compile with -march=x86-64

    mv28.C has

    void __attribute__ ((target("avx512vl"))) foo () {} /* { dg-error "ISA
'\[^\n\r\]*' is not supported in 'target' attribute, use 'arch=' syntax" } */
    ...

    to check for unsupported target attribute errors.  If AVX512 is enabled
    by default, there are no expected compiler errors.  Compile mv28.C with
    -march=x86-64 so that AVX512 isn't enabled on AVX512 machines when GCC
    is configured with

    --with-arch=native --with-cpu=native

            PR testsuite/126923
            * g++.target/i386/mv28.C (dg-additional-options): New.

    Signed-off-by: H.J. Lu <[email protected]>