Merge "Turn on LTO for libc++.so" am: 0860713e9e

Original change: https://android-review.googlesource.com/c/platform/external/libcxx/+/2623791

Change-Id: I1dd6a289739a070aea058f7c24b6f9c356000ab9
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>