[Patch] Break the Demangle -> Support dependency

[Rafael Espíndola via llvm-commits]

On 6 September 2016 at 16:18, Reid Kleckner <rnk at google.com> wrote:
> Do we intend to make this demangler asynch signal safe, i.e. not call malloc
> at all? If so, I vote keep the custom allocator. If not, I'd say nuke it.

Is that a requirement for the demangler in libcxxabi? Note that as it
is right now I think we would still call malloc in some cases (both
mallloc_alloc and arena::allocate).

Cheers,
Rafael