Opt host darwin libcxx out of LLD am: bf9a0bcb47 am: 7063e2d08e am: 310dd26fb1

Original change: https://android-review.googlesource.com/c/platform/external/libcxx/+/2133262

Change-Id: I75a6853513cbd4c7ab92a4177117a612094481e3
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>