[llvm] r179005 - AArch64: remove barriers from AArch64 atomic operations.

[Tim Northover]

> The sequentially
> consistent option is harder to demonstrate, but you should look at
> http://www0.cs.ucl.ac.uk/staff/j.alglave/papers/pldi12.pdf or
> http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2745.html for
> the style of argument you need.

Thanks, I'd not encountered that Power paper and it looks like it
could be just the kind of thing I could use. I understand there's only
one major difference in how the two behave.

Tim.