[PATCH] Respect object format choice on Darwin

[Jim Grosbach]

SGTM. Thanks, all.

> On Apr 30, 2015, at 12:44 PM, Rafael Espíndola <rafael.espindola at gmail.com> wrote:
> 
> On 7 February 2015 at 16:48, Keno Fischer <kfischer at college.harvard.edu> wrote:
>> @grosbach. Sorry I forgot about this. Pinging now :). I would guess it's possible to add a testcase. What should it do? Just check that the filetype is ELF when setting the triple to say `x86_64-apple-darwin14.0.0-elf`?
> 
> Just running llvm-mc on an empty .s file with that triple and checking
> that it produces an elf file should do it.
> 
> Cheers,
> Rafael