[PATCH] Darwin vararg parameters support in assembler macros

[Jim Grosbach]

Please add Tim Northover and Kevin Enderby as reviewers.

-jim
> On Jul 24, 2014, at 6:09 AM, Janne Grunau <j at jannau.net> wrote:
> 
> I would like to see this get merged.
> 
> This is the only missing feature to assemble libav/FFmpeg's aarch64 handwritten assembly code for ios/darwin.
> 
> libav/FFmpeg's test suite passes on cyclone using clang/llvm with this patch as assembler/compiler.
> 
> http://reviews.llvm.org/D3507
> 
>