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

[Jonathan Wakely via cfe-commits]

On 8 February 2016 at 19:23, Richard Smith wrote:
> "POD for the purpose of layout" is defined in the Itanium C++ ABI here:
>
>   http://mentorembedded.github.io/cxx-abi/abi.html#definitions

Thanks. So there's no problem using "POD for the purposes of layout",
and the change to "POD for the purpose of standard-layout" was
unnecessary and just confused things.