Enable in-tree libc++ builds on iOS

Binary size regression of about 109kB is expected -- please add
thomasanderson@ and thakis@ to the bug.

BUG=945054
R=thakis

Change-Id: Iaca4178e3b23b55a36af55d119d2eda2b76ef71d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1534897
Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
Auto-Submit: Thomas Anderson <thomasanderson@chromium.org>
Reviewed-by: Justin Cohen <justincohen@chromium.org>
Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#645001}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: dd9e27c0290618d32f50486ddb271704eab69999
2 files changed