Rolling v8/buildtools to 93b3d0af1b30db55ee42bd2e983f7753153217db

Rolling v8/tools/clang to eb87c73202018d13f2f713e1304ab4edf9a6f49f

TBR=jochen@chromium.org

Review URL: https://codereview.chromium.org/962223002

Cr-Commit-Position: refs/heads/master@{#26918}