Merge "Revert "Turn on LTO for libc++.so"" am: d3d779a3ff

Original change: https://android-review.googlesource.com/c/platform/external/libcxx/+/2644890

Change-Id: I02f55dd66868e71c9e02403407d7ef342bdc5f49
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>