Bump the minimal version required to compile DMD to 2.076.1

[Jacob Carlborg]

On 2018-01-12 19:45, Joakim wrote:

> For now, I think you have no choice but to simply work around whatever 
> that bug is.  We should drop support for 32-bit OS X sometime soon, and 
> if that fixes the issue, you have no problem.

Exactly. Apple will drop support for running 32bit applications in their 
next major OS release, 10.14.

-- 
/Jacob Carlborg