Update V8 DEPS.

Rolling v8/tools/clang to 71b766acbd4f2dbe860bcb57c003eba006244ae9

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

Review URL: https://codereview.chromium.org/1468333002

Cr-Commit-Position: refs/heads/master@{#32190}

DEPS

@@ -27,7 +27,7 @@ deps = {
   "v8/test/test262/data":
     Var("git_url") + "/external/github.com/tc39/test262.git" + "@" + "ea222fb7d09e334c321b987656315ad4056ded96",
   "v8/tools/clang":
-    Var("git_url") + "/chromium/src/tools/clang.git" + "@" + "f1ac92b46273db6ba0286cc1fe214d1aaa788f6d",
+    Var("git_url") + "/chromium/src/tools/clang.git" + "@" + "71b766acbd4f2dbe860bcb57c003eba006244ae9",
 }
 
 deps_os = {