Move Message::kDescriptorMethods to proto2::internal::kDescriptorMethods.

This allows upcoming changes to direclty instantiate ReflectionData by
removing protected accesses to a static member.

PiperOrigin-RevId: 866063775

Author: protobuf-github-bot

src/google/protobuf/compiler/cpp/message.cc

@@ -4075,7 +4075,7 @@ void MessageGenerator::GenerateClassData(io::Printer* p) {
                     false,
                     $v2_data$,
                 },
-                &$classname$::kDescriptorMethods,
+                &::_pbi::kDescriptorMethods,
                 &$desc_table$,
                 $tracker_on_get_metadata$,
             };

src/google/protobuf/compiler/java/java_features.pb.cc

@@ -65,6 +65,7 @@
 #include "google/protobuf/internal_metadata_locator.h"
 #include "google/protobuf/map.h"
 #include "google/protobuf/map_field.h"
+#include "google/protobuf/message.h"
 #include "google/protobuf/message_lite.h"
 #include "google/protobuf/micro_string.h"
 #include "google/protobuf/port.h"
@@ -395,7 +396,7 @@ struct DynamicMessageFactory::TypeInfo {
           PROTOBUF_FIELD_OFFSET(DynamicMessage, cached_byte_size_),
           false,
       },
-      &DynamicMessage::kDescriptorMethods,
+      &internal::kDescriptorMethods,
       nullptr,  // descriptor_table
       nullptr,  // get_metadata_tracker
   };