diff --git a/csharp/src/Google.Protobuf/Reflection/FeatureSetDescriptor.g.cs b/csharp/src/Google.Protobuf/Reflection/FeatureSetDescriptor.g.cs
new file mode 100644
index 0000000000..208ce1fcb6
--- /dev/null
+++ b/csharp/src/Google.Protobuf/Reflection/FeatureSetDescriptor.g.cs
@@ -0,0 +1,17 @@
+#region Copyright notice and license
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+//
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file or at
+// https://developers.google.com/open-source/licenses/bsd
+#endregion
+
+namespace Google.Protobuf.Reflection;
+
+internal sealed partial class FeatureSetDescriptor
+{
+    // Canonical serialized form of the edition defaults, generated by embed_edition_defaults.
+    private const string DefaultsBase64 =
+        "ChMYhAciACoMCAEQAhgCIAMoATACChMY5wciACoMCAIQARgBIAIoATABChMY6AciDAgBEAEYASACKAEwASoAIOYHKOgH";
+}
diff --git a/src/google/protobuf/any.pb.h b/src/google/protobuf/any.pb.h
index 1752068f80..3f867f851d 100644
--- a/src/google/protobuf/any.pb.h
+++ b/src/google/protobuf/any.pb.h
@@ -124,10 +124,7 @@ class PROTOBUF_EXPORT Any final
     return default_instance().GetMetadata().reflection;
   }
   static const Any& default_instance() {
-    return *internal_default_instance();
-  }
-  static inline const Any* internal_default_instance() {
-    return reinterpret_cast<const Any*>(
+    return *reinterpret_cast<const Any*>(
         &_Any_default_instance_);
   }
   static constexpr int kIndexInFileMessages = 0;
diff --git a/src/google/protobuf/api.pb.h b/src/google/protobuf/api.pb.h
index bf14193e52..488d4d4eb0 100644
--- a/src/google/protobuf/api.pb.h
+++ b/src/google/protobuf/api.pb.h
@@ -134,10 +134,7 @@ class PROTOBUF_EXPORT Mixin final
     return default_instance().GetMetadata().reflection;
   }
   static const Mixin& default_instance() {
-    return *internal_default_instance();
-  }
-  static inline const Mixin* internal_default_instance() {
-    return reinterpret_cast<const Mixin*>(
+    return *reinterpret_cast<const Mixin*>(
         &_Mixin_default_instance_);
   }
   static constexpr int kIndexInFileMessages = 2;
@@ -351,10 +348,7 @@ class PROTOBUF_EXPORT Method final
     return default_instance().GetMetadata().reflection;
   }
   static const Method& default_instance() {
-    return *internal_default_instance();
-  }
-  static inline const Method* internal_default_instance() {
-    return reinterpret_cast<const Method*>(
+    return *reinterpret_cast<const Method*>(
         &_Method_default_instance_);
   }
   static constexpr int kIndexInFileMessages = 1;
@@ -640,10 +634,7 @@ class PROTOBUF_EXPORT Api final
     return default_instance().GetMetadata().reflection;
   }
   static const Api& default_instance() {
-    return *internal_default_instance();
-  }
-  static inline const Api* internal_default_instance() {
-    return reinterpret_cast<const Api*>(
+    return *reinterpret_cast<const Api*>(
         &_Api_default_instance_);
   }
   static constexpr int kIndexInFileMessages = 0;
diff --git a/src/google/protobuf/duration.pb.h b/src/google/protobuf/duration.pb.h
index 90b466233e..1deb7cc939 100644
--- a/src/google/protobuf/duration.pb.h
+++ b/src/google/protobuf/duration.pb.h
@@ -124,10 +124,7 @@ class PROTOBUF_EXPORT Duration final
     return default_instance().GetMetadata().reflection;
   }
   static const Duration& default_instance() {
-    return *internal_default_instance();
-  }
-  static inline const Duration* internal_default_instance() {
-    return reinterpret_cast<const Duration*>(
+    return *reinterpret_cast<const Duration*>(
         &_Duration_default_instance_);
   }
   static constexpr int kIndexInFileMessages = 0;
diff --git a/src/google/protobuf/empty.pb.h b/src/google/protobuf/empty.pb.h
index 7dd59da6d8..128695f314 100644
--- a/src/google/protobuf/empty.pb.h
+++ b/src/google/protobuf/empty.pb.h
@@ -124,10 +124,7 @@ class PROTOBUF_EXPORT Empty final
     return default_instance().GetMetadata().reflection;
   }
   static const Empty& default_instance() {
-    return *internal_default_instance();
-  }
-  static inline const Empty* internal_default_instance() {
-    return reinterpret_cast<const Empty*>(
+    return *reinterpret_cast<const Empty*>(
         &_Empty_default_instance_);
   }
   static constexpr int kIndexInFileMessages = 0;
diff --git a/src/google/protobuf/field_mask.pb.h b/src/google/protobuf/field_mask.pb.h
index b6c2024cf8..bced0176dc 100644
--- a/src/google/protobuf/field_mask.pb.h
+++ b/src/google/protobuf/field_mask.pb.h
@@ -124,10 +124,7 @@ class PROTOBUF_EXPORT FieldMask final
     return default_instance().GetMetadata().reflection;
   }
   static const FieldMask& default_instance() {
-    return *internal_default_instance();
-  }
-  static inline const FieldMask* internal_default_instance() {
-    return reinterpret_cast<const FieldMask*>(
+    return *reinterpret_cast<const FieldMask*>(
         &_FieldMask_default_instance_);
   }
   static constexpr int kIndexInFileMessages = 0;
diff --git a/src/google/protobuf/source_context.pb.h b/src/google/protobuf/source_context.pb.h
index 20619ea89e..7fbb1edc7c 100644
--- a/src/google/protobuf/source_context.pb.h
+++ b/src/google/protobuf/source_context.pb.h
@@ -124,10 +124,7 @@ class PROTOBUF_EXPORT SourceContext final
     return default_instance().GetMetadata().reflection;
   }
   static const SourceContext& default_instance() {
-    return *internal_default_instance();
-  }
-  static inline const SourceContext* internal_default_instance() {
-    return reinterpret_cast<const SourceContext*>(
+    return *reinterpret_cast<const SourceContext*>(
         &_SourceContext_default_instance_);
   }
   static constexpr int kIndexInFileMessages = 0;
diff --git a/src/google/protobuf/struct.pb.h b/src/google/protobuf/struct.pb.h
index 1afaebad74..a9a3a8d0d2 100644
--- a/src/google/protobuf/struct.pb.h
+++ b/src/google/protobuf/struct.pb.h
@@ -181,10 +181,7 @@ class PROTOBUF_EXPORT ListValue final
     return default_instance().GetMetadata().reflection;
   }
   static const ListValue& default_instance() {
-    return *internal_default_instance();
-  }
-  static inline const ListValue* internal_default_instance() {
-    return reinterpret_cast<const ListValue*>(
+    return *reinterpret_cast<const ListValue*>(
         &_ListValue_default_instance_);
   }
   static constexpr int kIndexInFileMessages = 3;
@@ -382,10 +379,7 @@ class PROTOBUF_EXPORT Struct final
     return default_instance().GetMetadata().reflection;
   }
   static const Struct& default_instance() {
-    return *internal_default_instance();
-  }
-  static inline const Struct* internal_default_instance() {
-    return reinterpret_cast<const Struct*>(
+    return *reinterpret_cast<const Struct*>(
         &_Struct_default_instance_);
   }
   static constexpr int kIndexInFileMessages = 1;
@@ -625,7 +619,8 @@ class PROTOBUF_EXPORT Value final
     return default_instance().GetMetadata().reflection;
   }
   static const Value& default_instance() {
-    return *internal_default_instance();
+    return *reinterpret_cast<const Value*>(
+        &_Value_default_instance_);
   }
   enum KindCase {
     kNullValue = 1,
@@ -636,10 +631,6 @@ class PROTOBUF_EXPORT Value final
     kListValue = 6,
     KIND_NOT_SET = 0,
   };
-  static inline const Value* internal_default_instance() {
-    return reinterpret_cast<const Value*>(
-        &_Value_default_instance_);
-  }
   static constexpr int kIndexInFileMessages = 2;
   friend void swap(Value& a, Value& b) { a.Swap(&b); }
   inline void Swap(Value* other) {
diff --git a/src/google/protobuf/timestamp.pb.h b/src/google/protobuf/timestamp.pb.h
index f661142d8e..75a1cae732 100644
--- a/src/google/protobuf/timestamp.pb.h
+++ b/src/google/protobuf/timestamp.pb.h
@@ -124,10 +124,7 @@ class PROTOBUF_EXPORT Timestamp final
     return default_instance().GetMetadata().reflection;
   }
   static const Timestamp& default_instance() {
-    return *internal_default_instance();
-  }
-  static inline const Timestamp* internal_default_instance() {
-    return reinterpret_cast<const Timestamp*>(
+    return *reinterpret_cast<const Timestamp*>(
         &_Timestamp_default_instance_);
   }
   static constexpr int kIndexInFileMessages = 0;
diff --git a/src/google/protobuf/type.pb.h b/src/google/protobuf/type.pb.h
index 74a283ae3b..d94a4a37fd 100644
--- a/src/google/protobuf/type.pb.h
+++ b/src/google/protobuf/type.pb.h
@@ -286,10 +286,7 @@ class PROTOBUF_EXPORT Option final
     return default_instance().GetMetadata().reflection;
   }
   static const Option& default_instance() {
-    return *internal_default_instance();
-  }
-  static inline const Option* internal_default_instance() {
-    return reinterpret_cast<const Option*>(
+    return *reinterpret_cast<const Option*>(
         &_Option_default_instance_);
   }
   static constexpr int kIndexInFileMessages = 4;
@@ -503,10 +500,7 @@ class PROTOBUF_EXPORT Field final
     return default_instance().GetMetadata().reflection;
   }
   static const Field& default_instance() {
-    return *internal_default_instance();
-  }
-  static inline const Field* internal_default_instance() {
-    return reinterpret_cast<const Field*>(
+    return *reinterpret_cast<const Field*>(
         &_Field_default_instance_);
   }
   static constexpr int kIndexInFileMessages = 1;
@@ -890,10 +884,7 @@ class PROTOBUF_EXPORT EnumValue final
     return default_instance().GetMetadata().reflection;
   }
   static const EnumValue& default_instance() {
-    return *internal_default_instance();
-  }
-  static inline const EnumValue* internal_default_instance() {
-    return reinterpret_cast<const EnumValue*>(
+    return *reinterpret_cast<const EnumValue*>(
         &_EnumValue_default_instance_);
   }
   static constexpr int kIndexInFileMessages = 3;
@@ -1121,10 +1112,7 @@ class PROTOBUF_EXPORT Type final
     return default_instance().GetMetadata().reflection;
   }
   static const Type& default_instance() {
-    return *internal_default_instance();
-  }
-  static inline const Type* internal_default_instance() {
-    return reinterpret_cast<const Type*>(
+    return *reinterpret_cast<const Type*>(
         &_Type_default_instance_);
   }
   static constexpr int kIndexInFileMessages = 0;
@@ -1429,10 +1417,7 @@ class PROTOBUF_EXPORT Enum final
     return default_instance().GetMetadata().reflection;
   }
   static const Enum& default_instance() {
-    return *internal_default_instance();
-  }
-  static inline const Enum* internal_default_instance() {
-    return reinterpret_cast<const Enum*>(
+    return *reinterpret_cast<const Enum*>(
         &_Enum_default_instance_);
   }
   static constexpr int kIndexInFileMessages = 2;
diff --git a/src/google/protobuf/wrappers.pb.h b/src/google/protobuf/wrappers.pb.h
index 898afdfaec..c04b6c656c 100644
--- a/src/google/protobuf/wrappers.pb.h
+++ b/src/google/protobuf/wrappers.pb.h
@@ -156,10 +156,7 @@ class PROTOBUF_EXPORT UInt64Value final
     return default_instance().GetMetadata().reflection;
   }
   static const UInt64Value& default_instance() {
-    return *internal_default_instance();
-  }
-  static inline const UInt64Value* internal_default_instance() {
-    return reinterpret_cast<const UInt64Value*>(
+    return *reinterpret_cast<const UInt64Value*>(
         &_UInt64Value_default_instance_);
   }
   static constexpr int kIndexInFileMessages = 3;
@@ -351,10 +348,7 @@ class PROTOBUF_EXPORT UInt32Value final
     return default_instance().GetMetadata().reflection;
   }
   static const UInt32Value& default_instance() {
-    return *internal_default_instance();
-  }
-  static inline const UInt32Value* internal_default_instance() {
-    return reinterpret_cast<const UInt32Value*>(
+    return *reinterpret_cast<const UInt32Value*>(
         &_UInt32Value_default_instance_);
   }
   static constexpr int kIndexInFileMessages = 5;
@@ -546,10 +540,7 @@ class PROTOBUF_EXPORT StringValue final
     return default_instance().GetMetadata().reflection;
   }
   static const StringValue& default_instance() {
-    return *internal_default_instance();
-  }
-  static inline const StringValue* internal_default_instance() {
-    return reinterpret_cast<const StringValue*>(
+    return *reinterpret_cast<const StringValue*>(
         &_StringValue_default_instance_);
   }
   static constexpr int kIndexInFileMessages = 7;
@@ -746,10 +737,7 @@ class PROTOBUF_EXPORT Int64Value final
     return default_instance().GetMetadata().reflection;
   }
   static const Int64Value& default_instance() {
-    return *internal_default_instance();
-  }
-  static inline const Int64Value* internal_default_instance() {
-    return reinterpret_cast<const Int64Value*>(
+    return *reinterpret_cast<const Int64Value*>(
         &_Int64Value_default_instance_);
   }
   static constexpr int kIndexInFileMessages = 2;
@@ -941,10 +929,7 @@ class PROTOBUF_EXPORT Int32Value final
     return default_instance().GetMetadata().reflection;
   }
   static const Int32Value& default_instance() {
-    return *internal_default_instance();
-  }
-  static inline const Int32Value* internal_default_instance() {
-    return reinterpret_cast<const Int32Value*>(
+    return *reinterpret_cast<const Int32Value*>(
         &_Int32Value_default_instance_);
   }
   static constexpr int kIndexInFileMessages = 4;
@@ -1136,10 +1121,7 @@ class PROTOBUF_EXPORT FloatValue final
     return default_instance().GetMetadata().reflection;
   }
   static const FloatValue& default_instance() {
-    return *internal_default_instance();
-  }
-  static inline const FloatValue* internal_default_instance() {
-    return reinterpret_cast<const FloatValue*>(
+    return *reinterpret_cast<const FloatValue*>(
         &_FloatValue_default_instance_);
   }
   static constexpr int kIndexInFileMessages = 1;
@@ -1331,10 +1313,7 @@ class PROTOBUF_EXPORT DoubleValue final
     return default_instance().GetMetadata().reflection;
   }
   static const DoubleValue& default_instance() {
-    return *internal_default_instance();
-  }
-  static inline const DoubleValue* internal_default_instance() {
-    return reinterpret_cast<const DoubleValue*>(
+    return *reinterpret_cast<const DoubleValue*>(
         &_DoubleValue_default_instance_);
   }
   static constexpr int kIndexInFileMessages = 0;
@@ -1526,10 +1505,7 @@ class PROTOBUF_EXPORT BytesValue final
     return default_instance().GetMetadata().reflection;
   }
   static const BytesValue& default_instance() {
-    return *internal_default_instance();
-  }
-  static inline const BytesValue* internal_default_instance() {
-    return reinterpret_cast<const BytesValue*>(
+    return *reinterpret_cast<const BytesValue*>(
         &_BytesValue_default_instance_);
   }
   static constexpr int kIndexInFileMessages = 8;
@@ -1726,10 +1702,7 @@ class PROTOBUF_EXPORT BoolValue final
     return default_instance().GetMetadata().reflection;
   }
   static const BoolValue& default_instance() {
-    return *internal_default_instance();
-  }
-  static inline const BoolValue* internal_default_instance() {
-    return reinterpret_cast<const BoolValue*>(
+    return *reinterpret_cast<const BoolValue*>(
         &_BoolValue_default_instance_);
   }
   static constexpr int kIndexInFileMessages = 6;