Update clang-tools to ab/6172535 am: 23d676ad41

Change-Id: Ib199007ce92cd3bcc0914aefed7ced9a289fa8ab
tree: 51828eff344086a6865ff965ee49be54cc7ec0da
  1. darwin-x86/
  2. linux-x86/
  3. build-prebuilts.sh
  4. manifest.xml