[Trivial] Fix compiling ldc (ldc-druntime) on dragonfly

[dkgroot]

No description provided.

[JohanEngelen]

@dkgroot If you can find/provide a machine for CI, you can coordinate with @redstar in getting a buildbot worker set up for http://buildbot.ldc-developers.org/

[dkgroot]

@JohanEngelen Thanks for merging this so quickly :-)

I can provide a virtual machine (but might be a little slow and that might be annoying). I already have a CI (https://semaphoreci.com/dkgroot/ldc_dragonfly_ci) which was use to test the bootstrap (ltsmaster) part. Will contact @redstar to see what he would like to do.

[JohanEngelen]

We already use SemaphoreCI, so that'd work too.

[dkgroot]

@JohanEngelen If you look into my Semaphore version, you will notice that it currently has to run the ldc build inside qemu-system (on top of semaphore/linux) (The dragonfly installation is done once a day from the latest iso file). Not very economical but it was sort of a proof of concept for me.