[PATCH] doc: mention -mprefer-vector-width in target attrs

[Jeff Law]

On 2/3/21 8:15 AM, Martin Liška wrote:
> The patch documents -mprefer-vector-width which is a valid target
> attribute/pragma.
>
> Ready for master?
> Thanks,
> Martin
>
> gcc/ChangeLog:
>
>     * doc/extend.texi: Mention -mprefer-vector-width in target
>     attributes.
>
> gcc/testsuite/ChangeLog:
>
>     * gcc.target/i386/prefer-vector-width-attr.c: New test.
OK
jeff