Reenable libc++ on Windows

BUG=801780
R=thakis

Change-Id: Ife6f11c4e02534c879731274d427b0f563b8fa08
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1556590
Auto-Submit: Thomas Anderson <thomasanderson@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#652740}
1 file changed