[PATCH] Sema: reject probably incorrect atomic ordering requests

[Tim Northover]

Hi JF,

Thanks for taking a look.

On 11 March 2014 04:59, JF Bastien <jfb at google.com> wrote:
> lgtm after adding tests of missing __c11_atomic_* to test/Sema/atomic-ops.c,
> especially load_n/store_n.

I committed it with a full set of tests (r203561), and then changed it
to a warning (r203564) when I realised valid programs could contain
statements like:

if (0) {
  __c11_atomic_load(ptr, memory_order_release);
}

or possibly even some sane equivalent via templates or other weirdness.

Cheers.

Tim.