[libcxx] r284214 - XFAIL aligned allocation tests for older Clang versions

[Tim Northover via cfe-commits]

On 17 October 2016 at 09:11, Nico Weber via cfe-commits
<cfe-commits at lists.llvm.org> wrote:
> Looks like things are still unexpectedly passing at r284389 on macOS (but we
> currently only build and test libc++ on macOS, so maybe it's broken
> elsewhere too).

Green dragon is showing similar failures:
http://lab.llvm.org:8080/green/job/clang-stage1-cmake-RA-globalisel_check/4423/console,
though it claims to be using Xcode 7. I'll check how accurate that is
and run tests with libcxx locally too.

Tim.