Rolling v8/buildtools to de013cf87971d0ab40596f2275a633432c908052

Rolling v8/tools/clang to 05a5cb33164e3c656a3375a1614ab350ca799215

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

Review URL: https://codereview.chromium.org/1883703003

Cr-Commit-Position: refs/heads/master@{#35428}