Update clang-tools to ab/6661405

This commit includes:
aosp/1280621 Write relative paths to source_file fields in sdump
aosp/1345398 Write relative paths to name fields in sdump
aosp/1353527 Add -print-resource-dir to header-abi-dumper

Test: make
Bug: 157531581
Change-Id: I00fe254f322d300e843ed63320c4d30a9602d56b
27 files changed
tree: 84266b6517128349e2e8f4c9e30cbf70f479ad61
  1. darwin-x86/
  2. linux-x86/
  3. build-prebuilts.sh
  4. manifest.xml