[libstdc++, testsuite] Add dg-require-thread-fence

[Ville Voutilainen]

On 20 October 2016 at 20:08, Mike Stump <mikestump@comcast.net> wrote:
> So, from a test suite perspective, the correct fix it to make the port just work.  I have a bare metal port, I test libstdc++.
> I'd be curious to hear from the arm folks about it.


I daresay that would be the correct fix from many other perspectives
besides just from a test suite one. :)