[wwwdocs] gcc-9/changes.html - Mention new OpenRISC backend

[Gerald Pfeifer]

On Wed, 10 Apr 2019, Stafford Horne wrote:
> Committed.

Thanks!

> It turns out I do have CVS access, which is granted along with SVN access.

Yes, you do, and you are very welcome making changes like this
(plus anything that remotely qualifies as obvious). :-)

If you have a recommendation (or patch) on what would have helped
you get started around wwwdocs, that would be great.

Thanks,
Gerald