RFC: Update Intel386, x86-64 and IA MCU psABIs for passing/returning empty struct

[Matthijs van Duin via cfe-commits]

On 20 February 2016 at 23:35, H.J. Lu <hjl.tools at gmail.com> wrote:
> Can a compiler tell if a copy constructor or destructor is trivial
> from the class declaration without function body?

Yes, the mere presence of the declaration suffices to render it
non-trivial (unless explicitly declared "= default" like I did with
the default constructor, in which case there's no function body).