regenerate code

csharp/src/Google.Protobuf.Test.TestProtos/Unittest.cs

diff --git a/csharp/src/Google.Protobuf.Test.TestProtos/Unittest.cs b/csharp/src/Google.Protobuf.Test.TestProtos/Unittest.cs
index ab8e55d..a843c4a 100644
--- a/csharp/src/Google.Protobuf.Test.TestProtos/Unittest.cs
+++ b/csharp/src/Google.Protobuf.Test.TestProtos/Unittest.cs
@@ -2949,9 +2949,9 @@
       repeatedNestedMessage_.WriteTo(output, _repeated_repeatedNestedMessage_codec);
       repeatedForeignMessage_.WriteTo(output, _repeated_repeatedForeignMessage_codec);
       repeatedImportMessage_.WriteTo(output, _repeated_repeatedImportMessage_codec);
-      repeatedNestedEnum_.WriteTo(ref output, _repeated_repeatedNestedEnum_codec);
-      repeatedForeignEnum_.WriteTo(ref output, _repeated_repeatedForeignEnum_codec);
-      repeatedImportEnum_.WriteTo(ref output, _repeated_repeatedImportEnum_codec);
+      repeatedNestedEnum_.WriteTo(output, _repeated_repeatedNestedEnum_codec);
+      repeatedForeignEnum_.WriteTo(output, _repeated_repeatedForeignEnum_codec);
+      repeatedImportEnum_.WriteTo(output, _repeated_repeatedImportEnum_codec);
       repeatedStringPiece_.WriteTo(output, _repeated_repeatedStringPiece_codec);
       repeatedCord_.WriteTo(output, _repeated_repeatedCord_codec);
       repeatedLazyMessage_.WriteTo(output, _repeated_repeatedLazyMessage_codec);
@@ -14258,7 +14258,7 @@
       }
       repeatedPrimitiveField_.WriteTo(output, _repeated_repeatedPrimitiveField_codec);
       repeatedStringField_.WriteTo(output, _repeated_repeatedStringField_codec);
-      repeatedEnumField_.WriteTo(ref output, _repeated_repeatedEnumField_codec);
+      repeatedEnumField_.WriteTo(output, _repeated_repeatedEnumField_codec);
       repeatedMessageField_.WriteTo(output, _repeated_repeatedMessageField_codec);
       repeatedStringPieceField_.WriteTo(output, _repeated_repeatedStringPieceField_codec);
       repeatedCordField_.WriteTo(output, _repeated_repeatedCordField_codec);
@@ -22901,7 +22901,7 @@
       packedFloat_.WriteTo(output, _repeated_packedFloat_codec);
       packedDouble_.WriteTo(output, _repeated_packedDouble_codec);
       packedBool_.WriteTo(output, _repeated_packedBool_codec);
-      packedEnum_.WriteTo(ref output, _repeated_packedEnum_codec);
+      packedEnum_.WriteTo(output, _repeated_packedEnum_codec);
       if (_unknownFields != null) {
         _unknownFields.WriteTo(output);
       }
@@ -23419,7 +23419,7 @@
       unpackedFloat_.WriteTo(output, _repeated_unpackedFloat_codec);
       unpackedDouble_.WriteTo(output, _repeated_unpackedDouble_codec);
       unpackedBool_.WriteTo(output, _repeated_unpackedBool_codec);
-      unpackedEnum_.WriteTo(ref output, _repeated_unpackedEnum_codec);
+      unpackedEnum_.WriteTo(output, _repeated_unpackedEnum_codec);
       if (_unknownFields != null) {
         _unknownFields.WriteTo(output);
       }