C++ PATCH to add test for c++/91104

[Jason Merrill]

On 7/17/19 1:51 PM, Marek Polacek wrote:
> This was a wrong code issue where we printed
> 2 3 1
> 1 2 3
> instead of
> 1 2 3
> 1 2 3
> but it was fixed by r271705.  I don't know of a good way to check
> the auto... expansion here so I used dg-output.

You could call another function with the expansion and check the 
arguments there?

Jason