Merge pull request janestreet#98 from kit-ty-kate/412

OCaml 4.12 support

Backport 50f3b3e.

Merge pull request janestreet#85 from kit-ty-kate/410

Add support for OCaml 4.10

Relax OCaml upper bound.

Merge pull request janestreet#74 from janestreet/v0.12.0-for-win

backport fix for popcount detection on windows

Fix for janestreet#67.

Distribution v0.11.1