Have Arena::Create support arena constructible types
Unlike Arena::CreateMessage, Arena::Create creates only the top level object
from arena even if it is arena constructalble; e.g. messages, RepeatedPtrField,
etc. This renders arenas less effective.
Instead of asking users to be aware of such nuances to use the right API for
the right type, this CL makes Arena::Create recognizes and fully supports arena
constructable types.
While extremly rare, some users try to emulate Arena::CreateMessage with
Arena::Create by passing arena parameter twice. For example,
```
auto foo = Arena::Create<Foo>(&arena, &arena); // bad
```
This pattern is not supported and will break after this change. The following
is recommended instead.
```
auto foo = Arena::CreateMessage<Foo>(&arena); // recommended
auto foo = Arena::Create<Foo>(&arena); // after this change
```
PiperOrigin-RevId: 585709990
diff --git a/cmake/abseil-cpp.cmake b/cmake/abseil-cpp.cmake
index b50fb89..a4e9d22 100644
--- a/cmake/abseil-cpp.cmake
+++ b/cmake/abseil-cpp.cmake
@@ -72,6 +72,7 @@
absl::flat_hash_set
absl::function_ref
absl::hash
+ absl::if_constexpr
absl::layout
absl::log_initialize
absl::log_severity
