[PING^2, AArch64] Add long-call attribute and pragma interfaces

[Yangfei (Felix)]

Patch ping ...


> 
> > On 04/02/2015 11:59 PM, Yangfei (Felix) wrote:
> > > Patch ping: https://gcc.gnu.org/ml/gcc-patches/2014-11/msg01148.html
> >
> > This patch needs documentation for the new attributes and pragmas
> > before it can be committed.  (Since this is a new feature I think it
> > has to wait until stage 1, too, but that's not my call.)
> >
> > -Sandra
> 
> 
> Sure, I will update the docs when this patch is approved by the port maintainers.
> I didn't get any feedback from Richard for the v2 patch.  Thanks.