This enhances to use the native parallel compile extensions if available. Bug: 873724 Change-Id: I0aaed314accd75e1bfa596b322225b56d729d3a6 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1475234 Commit-Queue: Jie A Chen <jie.a.chen@intel.com> Reviewed-by: Jamie Madill <jmadill@chromium.org>
