Update V8 DEPS.

Rolling v8/tools/clang: https://chromium.googlesource.com/chromium/src/tools/clang/+log/b6fe934..0a9737b

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

Change-Id: I85267bc7ecb1fc6cb53cfd761f414147b3d47d73
Reviewed-on: https://chromium-review.googlesource.com/958684Reviewed-by: v8 autoroll <v8-autoroll@chromium.org>
Commit-Queue: v8 autoroll <v8-autoroll@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51865}

DEPS

@@ -59,7 +59,7 @@ deps = {
   'v8/test/test262/harness':
     Var('chromium_url') + '/external/github.com/test262-utils/test262-harness-py.git' + '@' + '0f2acdd882c84cff43b9d60df7574a1901e2cdcd',
   'v8/tools/clang':
-    Var('chromium_url') + '/chromium/src/tools/clang.git' + '@' + 'b6fe9347a6dba2ec8f5c59c088ba47de87442529',
+    Var('chromium_url') + '/chromium/src/tools/clang.git' + '@' + '0a9737b9d40402c2fc36afb1349f3abdf7eb1f38',
   'v8/tools/luci-go':
     Var('chromium_url') + '/chromium/src/tools/luci-go.git' + '@' + 'ff0709d4283b1f233dcf0c9fec1672c6ecaed2f1',
   'v8/test/wasm-js':