Add targets of symlinks to genrule's sources am: f45e673a55 am: 7cb8ae6d95

Original change: https://android-review.googlesource.com/c/platform/external/libcxx/+/2853249

Change-Id: I3357fdb4a49fbb58ac98579cd8e5d35faefb6afe
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>