Breaking change: Make the arena-enabled constructors of RepeatedField, RepeatedPtrField, and Map private.

If you would like to construct one of these fields with arena storage, you must construct them on an arena.

For example:
```cc
RepeatedPtrField<MyMessage> rpf(arena);
```

should be changed to:
```cc
auto* rpf = Arena::Create<RepeatedPtrField<MyMessage>>(arena);
```

PiperOrigin-RevId: 820040847

Author: ClaytonKnittel

src/google/protobuf/map.h

@@ -1181,22 +1181,12 @@ class Map : private internal::KeyMapBase<internal::KeyForBase<Key>> {
     CopyFromImpl(arena(), other);
   }
 #else
-  // If PROTOBUF_FUTURE_REMOVE_MAP_FIELD_ARENA_CONSTRUCTOR is defined, make the
-  // arena-enabled constructor private.
-#ifdef PROTOBUF_FUTURE_REMOVE_MAP_FIELD_ARENA_CONSTRUCTOR
 
  private:
-#endif
   explicit Map(Arena* arena) : Base(arena, GetTypeInfo()) {
     StaticValidityCheck();
   }
 
-  // If PROTOBUF_FUTURE_REMOVE_MAP_FIELD_ARENA_CONSTRUCTOR was not defined, we
-  // need to add the private tag here.
-#ifndef PROTOBUF_FUTURE_REMOVE_MAP_FIELD_ARENA_CONSTRUCTOR
-
- private:
-#endif
   Map(Arena* arena, const Map& other) : Map(arena) {
     StaticValidityCheck();
     CopyFromImpl(arena, other);

src/google/protobuf/port_def.inc

@@ -161,18 +161,6 @@ static_assert(PROTOBUF_ABSL_MIN(20230125, 3),
 // Owner: cknittel@, mkruskal@
 #define PROTOBUF_FUTURE_NO_RECURSIVE_MESSAGE_COPY 1
 
-// Removes the public RepeatedPtrField(Arena*) constructor.
-// Owner: cknittel@, mkruskal@
-#define PROTOBUF_FUTURE_REMOVE_REPEATED_PTR_FIELD_ARENA_CONSTRUCTOR 1
-
-// Removes the public Map(Arena*) constructor.
-// Owner: cknittel@, mkruskal@
-#define PROTOBUF_FUTURE_REMOVE_MAP_FIELD_ARENA_CONSTRUCTOR 1
-
-// Removes the public RepeatedField(Arena*) constructor.
-// Owner: cknittel@, mkruskal@
-#define PROTOBUF_FUTURE_REMOVE_REPEATED_FIELD_ARENA_CONSTRUCTOR 1
-
 #else
 
 #define PROTOBUF_FUTURE_ADD_NODISCARD

src/google/protobuf/port_undef.inc

@@ -77,8 +77,6 @@
 #undef PROTOBUF_FUTURE_REMOVE_CREATEMESSAGE
 #undef PROTOBUF_FUTURE_ADD_NODISCARD
 #undef PROTOBUF_FUTURE_NO_RECURSIVE_MESSAGE_COPY
-#undef PROTOBUF_FUTURE_REMOVE_REPEATED_PTR_FIELD_ARENA_CONSTRUCTOR
-#undef PROTOBUF_FUTURE_REMOVE_MAP_FIELD_ARENA_CONSTRUCTOR
 #endif
 
 #include "google/protobuf/os_macros_restore.inc"

src/google/protobuf/repeated_field.h

@@ -403,13 +403,6 @@ class ABSL_ATTRIBUTE_WARN_UNUSED PROTOBUF_DECLSPEC_EMPTY_BASES
   RepeatedField(const RepeatedField& rhs) : RepeatedField(nullptr, rhs) {}
 #endif
 
-#ifndef PROTOBUF_INTERNAL_REMOVE_ARENA_PTRS_REPEATED_FIELD
-#ifndef PROTOBUF_FUTURE_REMOVE_REPEATED_FIELD_ARENA_CONSTRUCTOR
-  // TODO: make this constructor private
-  explicit RepeatedField(Arena* arena);
-#endif
-#endif
-
   template <typename Iter,
             typename = typename std::enable_if<std::is_constructible<
                 Element, decltype(*std::declval<Iter>())>::value>::type>
@@ -630,10 +623,8 @@ class ABSL_ATTRIBUTE_WARN_UNUSED PROTOBUF_DECLSPEC_EMPTY_BASES
 
   friend class internal::FieldWithArena<RepeatedField<Element>>;
 
-#ifdef PROTOBUF_FUTURE_REMOVE_REPEATED_FIELD_ARENA_CONSTRUCTOR
   // For access to private arena constructor.
   friend class UnknownFieldSet;
-#endif
 
   static constexpr int kSooCapacityElements =
       internal::SooCapacityElements<Element>();
@@ -647,9 +638,7 @@ class ABSL_ATTRIBUTE_WARN_UNUSED PROTOBUF_DECLSPEC_EMPTY_BASES
                 const RepeatedField& rhs);
   RepeatedField(internal::InternalMetadataOffset offset, RepeatedField&& rhs);
 #else
-#ifdef PROTOBUF_FUTURE_REMOVE_REPEATED_FIELD_ARENA_CONSTRUCTOR
   explicit RepeatedField(Arena* arena);
-#endif
 
   RepeatedField(Arena* arena, const RepeatedField& rhs);
   RepeatedField(Arena* arena, RepeatedField&& rhs);

src/google/protobuf/repeated_ptr_field.h

@@ -1149,12 +1149,6 @@ class ABSL_ATTRIBUTE_WARN_UNUSED RepeatedPtrField final
   RepeatedPtrField(internal::InternalVisibility, Arena* arena,
                    RepeatedPtrField&& rhs)
       : RepeatedPtrField(arena, std::move(rhs)) {}
-
-#ifndef PROTOBUF_FUTURE_REMOVE_REPEATED_PTR_FIELD_ARENA_CONSTRUCTOR
-  // TODO: make constructor private
-  [[deprecated("Use Arena::Create<RepeatedPtrField<...>>(Arena*) instead")]]
-  explicit RepeatedPtrField(Arena* arena);
-#endif
 #endif  // !PROTOBUF_INTERNAL_REMOVE_ARENA_PTRS_REPEATED_PTR_FIELD
 
   template <typename Iter,
@@ -1504,9 +1498,7 @@ class ABSL_ATTRIBUTE_WARN_UNUSED RepeatedPtrField final
   RepeatedPtrField(Arena* arena, const RepeatedPtrField& rhs);
   RepeatedPtrField(Arena* arena, RepeatedPtrField&& rhs);
 
-#ifdef PROTOBUF_FUTURE_REMOVE_REPEATED_PTR_FIELD_ARENA_CONSTRUCTOR
   explicit RepeatedPtrField(Arena* arena);
-#endif
 #endif  // !PROTOBUF_INTERNAL_REMOVE_ARENA_PTRS_REPEATED_PTR_FIELD