[opus] non-standard alloca.h

[Gregory Maxwell]

On Tue, Nov 26, 2013 at 10:35 PM, LRN <lrn1986 at gmail.com> wrote:
> AFAIK, alloca.h is not POSIX. Here's a patch that includes alloca.h
> only when it's really there.
> It also includes malloc.h, which is where mingw-w64 defines the
> alloca() macro, mapping it to gcc __builtin_alloca() or to msvcrt
> _alloca().

This whole path is only triggered when the compiler is unable to use
C99 var arrays. Did you actually bump into this with something that
can use configure? (e.g. do we have a problem with the var array test
someplace)