Add a tool/script to run clang-tidy over V8.

Change-Id: I6d20cb2febdcf8c937d5b37557a701d9c6c45fd2
Reviewed-on: https://chromium-review.googlesource.com/1177720
Commit-Queue: Florian Sattler <sattlerf@google.com>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55786}

.clang-tidy

+---
+---
+  Checks:          '-*,
+                    modernize-redundant-void-arg,
+                    modernize-replace-random-shuffle,
+                    modernize-shrink-to-fit,
+                    modernize-use-auto,
+                    modernize-use-bool-literals,
+                    modernize-use-equals-default,
+                    modernize-use-equals-delete,
+                    modernize-use-nullptr,
+                    modernize-use-override,
+                    google-build-explicit-make-pair,
+                    google-explicit-constructor,
+                    google-readability-casting'
+WarningsAsErrors: ''
+HeaderFilterRegex: ''
+AnalyzeTemporaryDtors: false
+...
+