Rolling v8/tools/clang: https://chromium.googlesource.com/chromium/src/tools/clang/+log/a1420b8..5bad4f2

TBR=machenbach@chromium.org,hablich@chromium.org

Change-Id: I7cf78bd76d7a5126194bfcb5538803de8e6ea601
Reviewed-on: https://chromium-review.googlesource.com/612852Reviewed-by: v8 autoroll <v8-autoroll@chromium.org>
Commit-Queue: v8 autoroll <v8-autoroll@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47329}