Rolling v8/build: https://chromium.googlesource.com/chromium/src/build/+log/c94e6d2..70270c1

Rolling v8/tools/clang: https://chromium.googlesource.com/chromium/src/tools/clang/+log/3a41cc3..7a4c8c9

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

Review-Url: https://codereview.chromium.org/2644793002
Cr-Commit-Position: refs/heads/master@{#42488}