Change _Extensions property to normal body rather than expression
diff --git a/csharp/src/Google.Protobuf.Test/TestProtos/TestMessagesProto2.cs b/csharp/src/Google.Protobuf.Test/TestProtos/TestMessagesProto2.cs
index 2f25195..350fb7c 100644
--- a/csharp/src/Google.Protobuf.Test/TestProtos/TestMessagesProto2.cs
+++ b/csharp/src/Google.Protobuf.Test/TestProtos/TestMessagesProto2.cs
@@ -248,7 +248,7 @@
     private static readonly pb::MessageParser<TestAllTypesProto2> _parser = new pb::MessageParser<TestAllTypesProto2>(() => new TestAllTypesProto2());
     private pb::UnknownFieldSet _unknownFields;
     private pb::ExtensionSet<TestAllTypesProto2> _extensions;
-    private pb::ExtensionSet<TestAllTypesProto2> _Extensions => _extensions;
+    private pb::ExtensionSet<TestAllTypesProto2> _Extensions { get { return _extensions; } }
     private int _hasBits0;
     private int _hasBits1;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
@@ -4319,7 +4319,7 @@
         private static readonly pb::MessageParser<MessageSetCorrect> _parser = new pb::MessageParser<MessageSetCorrect>(() => new MessageSetCorrect());
         private pb::UnknownFieldSet _unknownFields;
         private pb::ExtensionSet<MessageSetCorrect> _extensions;
-        private pb::ExtensionSet<MessageSetCorrect> _Extensions => _extensions;
+        private pb::ExtensionSet<MessageSetCorrect> _Extensions { get { return _extensions; } }
         [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
         public static pb::MessageParser<MessageSetCorrect> Parser { get { return _parser; } }
 
diff --git a/csharp/src/Google.Protobuf.Test/TestProtos/Unittest.cs b/csharp/src/Google.Protobuf.Test/TestProtos/Unittest.cs
index 2e1930d..e55df12 100644
--- a/csharp/src/Google.Protobuf.Test/TestProtos/Unittest.cs
+++ b/csharp/src/Google.Protobuf.Test/TestProtos/Unittest.cs
@@ -5139,7 +5139,7 @@
     private static readonly pb::MessageParser<TestAllExtensions> _parser = new pb::MessageParser<TestAllExtensions>(() => new TestAllExtensions());
     private pb::UnknownFieldSet _unknownFields;
     private pb::ExtensionSet<TestAllExtensions> _extensions;
-    private pb::ExtensionSet<TestAllExtensions> _Extensions => _extensions;
+    private pb::ExtensionSet<TestAllExtensions> _Extensions { get { return _extensions; } }
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<TestAllExtensions> Parser { get { return _parser; } }
 
@@ -5914,7 +5914,7 @@
     private static readonly pb::MessageParser<TestGroupExtension> _parser = new pb::MessageParser<TestGroupExtension>(() => new TestGroupExtension());
     private pb::UnknownFieldSet _unknownFields;
     private pb::ExtensionSet<TestGroupExtension> _extensions;
-    private pb::ExtensionSet<TestGroupExtension> _Extensions => _extensions;
+    private pb::ExtensionSet<TestGroupExtension> _Extensions { get { return _extensions; } }
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<TestGroupExtension> Parser { get { return _parser; } }
 
@@ -8485,7 +8485,7 @@
     private static readonly pb::MessageParser<TestEmptyMessageWithExtensions> _parser = new pb::MessageParser<TestEmptyMessageWithExtensions>(() => new TestEmptyMessageWithExtensions());
     private pb::UnknownFieldSet _unknownFields;
     private pb::ExtensionSet<TestEmptyMessageWithExtensions> _extensions;
-    private pb::ExtensionSet<TestEmptyMessageWithExtensions> _Extensions => _extensions;
+    private pb::ExtensionSet<TestEmptyMessageWithExtensions> _Extensions { get { return _extensions; } }
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<TestEmptyMessageWithExtensions> Parser { get { return _parser; } }
 
@@ -8626,7 +8626,7 @@
     private static readonly pb::MessageParser<TestMultipleExtensionRanges> _parser = new pb::MessageParser<TestMultipleExtensionRanges>(() => new TestMultipleExtensionRanges());
     private pb::UnknownFieldSet _unknownFields;
     private pb::ExtensionSet<TestMultipleExtensionRanges> _extensions;
-    private pb::ExtensionSet<TestMultipleExtensionRanges> _Extensions => _extensions;
+    private pb::ExtensionSet<TestMultipleExtensionRanges> _Extensions { get { return _extensions; } }
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<TestMultipleExtensionRanges> Parser { get { return _parser; } }
 
@@ -11936,7 +11936,7 @@
     private static readonly pb::MessageParser<TestFieldOrderings> _parser = new pb::MessageParser<TestFieldOrderings>(() => new TestFieldOrderings());
     private pb::UnknownFieldSet _unknownFields;
     private pb::ExtensionSet<TestFieldOrderings> _extensions;
-    private pb::ExtensionSet<TestFieldOrderings> _Extensions => _extensions;
+    private pb::ExtensionSet<TestFieldOrderings> _Extensions { get { return _extensions; } }
     private int _hasBits0;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<TestFieldOrderings> Parser { get { return _parser; } }
@@ -19250,7 +19250,7 @@
     private static readonly pb::MessageParser<TestPackedExtensions> _parser = new pb::MessageParser<TestPackedExtensions>(() => new TestPackedExtensions());
     private pb::UnknownFieldSet _unknownFields;
     private pb::ExtensionSet<TestPackedExtensions> _extensions;
-    private pb::ExtensionSet<TestPackedExtensions> _Extensions => _extensions;
+    private pb::ExtensionSet<TestPackedExtensions> _Extensions { get { return _extensions; } }
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<TestPackedExtensions> Parser { get { return _parser; } }
 
@@ -19391,7 +19391,7 @@
     private static readonly pb::MessageParser<TestUnpackedExtensions> _parser = new pb::MessageParser<TestUnpackedExtensions>(() => new TestUnpackedExtensions());
     private pb::UnknownFieldSet _unknownFields;
     private pb::ExtensionSet<TestUnpackedExtensions> _extensions;
-    private pb::ExtensionSet<TestUnpackedExtensions> _Extensions => _extensions;
+    private pb::ExtensionSet<TestUnpackedExtensions> _Extensions { get { return _extensions; } }
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<TestUnpackedExtensions> Parser { get { return _parser; } }
 
@@ -20294,7 +20294,7 @@
     private static readonly pb::MessageParser<TestParsingMerge> _parser = new pb::MessageParser<TestParsingMerge>(() => new TestParsingMerge());
     private pb::UnknownFieldSet _unknownFields;
     private pb::ExtensionSet<TestParsingMerge> _extensions;
-    private pb::ExtensionSet<TestParsingMerge> _Extensions => _extensions;
+    private pb::ExtensionSet<TestParsingMerge> _Extensions { get { return _extensions; } }
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<TestParsingMerge> Parser { get { return _parser; } }
 
@@ -22571,7 +22571,7 @@
     private static readonly pb::MessageParser<TestHugeFieldNumbers> _parser = new pb::MessageParser<TestHugeFieldNumbers>(() => new TestHugeFieldNumbers());
     private pb::UnknownFieldSet _unknownFields;
     private pb::ExtensionSet<TestHugeFieldNumbers> _extensions;
-    private pb::ExtensionSet<TestHugeFieldNumbers> _Extensions => _extensions;
+    private pb::ExtensionSet<TestHugeFieldNumbers> _Extensions { get { return _extensions; } }
     private int _hasBits0;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<TestHugeFieldNumbers> Parser { get { return _parser; } }
@@ -23426,7 +23426,7 @@
     private static readonly pb::MessageParser<TestExtensionInsideTable> _parser = new pb::MessageParser<TestExtensionInsideTable>(() => new TestExtensionInsideTable());
     private pb::UnknownFieldSet _unknownFields;
     private pb::ExtensionSet<TestExtensionInsideTable> _extensions;
-    private pb::ExtensionSet<TestExtensionInsideTable> _Extensions => _extensions;
+    private pb::ExtensionSet<TestExtensionInsideTable> _Extensions { get { return _extensions; } }
     private int _hasBits0;
     [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
     public static pb::MessageParser<TestExtensionInsideTable> Parser { get { return _parser; } }