Changing default cxx_stdlib to libc++

[Ryan Schmidt]

On Mar 14, 2018, at 07:23, db wrote:
> On 14 Mar 2018, at 01:14, Rainer Müller wrote:
>> Are you going to sponsor a dedicated Mac server for GitLab CI?
>> Travis CI is available at no cost and we have no funds to pay for anything.
> 
> If MacPorts is short on resources, these could be listed on the website. Folks can certainly ask around.

We did have an offer on the list some months ago from someone with spare Mac hardware in a data center that they would let us use. We did not respond to the offer. I'm not sure how comfortable I am accepting unsolicited infrastructure offers from unfamiliar parties.