[DOC Patch] Add sample for @cc constraint

[Bernd Schmidt]

On 04/16/2016 01:12 AM, David Wohlferd wrote:
> There were  basically 3 changes I was trying for in that doc patch. Are
> any of them worth keeping?  Or are we done?
>
> 1) "Do not clobber flags if they are being used as outputs."
> 2) Output flags sample (with #if removed).
> 3) "On the x86 platform, flags are always treated as clobbered by
> extended asm whether @code{"cc"} is specified or not."
>
> I'm prepared to send an updated patch if there's anything here that
> might get approved.

I think the updated flags sample would be nice to have.


Bernd