Update clang-tools to ab/6450978 am: 8984d81cea am: 1c3632ca18

Change-Id: I3ea48d200038a393f13d2579e615d020b0c27aed
tree: bcf6c4afcea8361d677531a3c57dbd3738feec6d
  1. darwin-x86/
  2. linux-x86/
  3. build-prebuilts.sh
  4. manifest.xml