Rolling v8/build: https://chromium.googlesource.com/chromium/src/build/+log/6167734..9c1e28b

Rolling v8/tools/clang: https://chromium.googlesource.com/chromium/src/tools/clang/+log/bd3b137..8427dae

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

Change-Id: Id8b75c73794c8d13dce3322a49d9259d02529ee4
Reviewed-on: https://chromium-review.googlesource.com/784472Reviewed-by: v8 autoroll <v8-autoroll@chromium.org>
Commit-Queue: v8 autoroll <v8-autoroll@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49559}