[absl] Change Abseil include rules to allowlist

Copy the initial allowlist (and banned list) from relevant entries in
the Chromium guidelines.

Change-Id: Id22566ffe97e36f0c139d05218e94448f10a790f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3168281
Auto-Submit: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/main@{#76942}

DEPS

@@ -325,11 +325,21 @@ deps = {
 
 include_rules = [
   # Everybody can use some things.
-  '+absl',
   '+include',
   '+unicode',
   '+third_party/fdlibm',
-  '+third_party/ittapi/include'
+  '+third_party/ittapi/include',
+  # Abseil features are allow-listed. Please use your best judgement when adding
+  # to this set -- if in doubt, email v8-dev@. For general guidance, refer to
+  # the Chromium guidelines (though note that some requirements in V8 may be
+  # different to Chromium's):
+  # https://chromium.googlesource.com/chromium/src/+/main/styleguide/c++/c++11.md
+  '+absl/types/optional.h',
+  '+absl/types/variant.h',
+  '+absl/status',
+  # Some abseil features are explicitly banned.
+  '-absl/types/any.h', # Requires RTTI.
+  '-absl/types/flags', # Requires RTTI.
 ]
 
 # checkdeps.py shouldn't check for includes in these directories: