Update V8 DEPS.
Update V8 DEPS.

Rolling v8/tools/clang to e64bdee4434b184d13a8f2cce79b65cd18e02ee2

TBR=machenbach@chromium.org

Review URL: https://codereview.chromium.org/919473003

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#26562}

UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh