Add targets of symlinks to genrule's sources am: f45e673a55 am: 7cb8ae6d95 am: 5758097fe7

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

Change-Id: I1e4f1ed6d474b316d284e65d32867c5acca26c98
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>