[PATCH 8 of 9] util: support multi-threaded zstandard compression for bundles

[Yuya Nishihara]

On Thu, 6 Apr 2017 10:51:36 -0700, Gregory Szorc wrote:
> Does anyone see any value in adding it as an experimental config option in
> Mercurial? Or should we drop the feature for now? I'd kinda like it there
> to make it easier to experiment with. But if others aren't comfortable with
> it, I totally understand.

An experimental config makes sense to me. My only concern was a hard bug
in C layer, but that would be okay-ish for experimental features.