[tlbuild] Tweak for harfbuzz

[Richard Koch]

Karl and Friends,

Seeing the message below, I downloaded and compiled everything including xindy on El Capitan.
There were no errors and no test failures and I got 429 executables.

(In 2018, MacTeX supports El Capitan, Sierra, and High Sierra, together with the system
which Apple will give developers in June and release next September.)

Dick Koch



> On Jan 10, 2018, at 1:39 PM, Karl Berry <karl at freefriends.org> wrote:
> 
> I hope this means that all the other painful changes we committed
> yesterday (new poppler, new luatex, C++11 for both) do build on Cygwin ...k