Implement C1X _Alignas, _Alignof, max_align_t, stdalign.h

[Jonathan Wakely]

On 6 December 2011 07:12, Miles Bader wrote:
> BTW, is there a reason that C1X _Alignas is supported, but not C++11
> alignas?  Is the latter harder?

Huh, for some reason I thought it already was.  That makes the
stdalign.h part of my patch wrong then.