Merge "Don't discard the result of std::unique" into main am: d0210ae77c am: cffa43f6df

Original change: https://android-review.googlesource.com/c/platform/external/clang/+/2755601

Change-Id: Idfcb11953376fd24b7a1998e17d974bd73110273
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>