[compiler-rt] r269587 - Fix FreeBSD build failure

[Joerg Sonnenberger via llvm-commits]

On Sun, May 15, 2016 at 04:26:18AM -0000, Xinliang David Li via llvm-commits wrote:
> Author: davidxl
> Date: Sat May 14 23:26:17 2016
> New Revision: 269587
> 
> URL: http://llvm.org/viewvc/llvm-project?rev=269587&view=rev
> Log:
> Fix FreeBSD build failure

This will be needed on all BSDs. I wonder if we shouldn't just use:
#elif defined(__GNUC__)
#define alloca(x) __builtin_alloca(x)

Joerg