Regenerate conformance files to include extra oneof fields.

This should fix the failures in the conformance tests - although
it highlights the problem that we need to do this when changing
the conformance.proto file...

conformance/failure_list_csharp.txt

@@ -5,23 +5,3 @@ JsonInput.FieldNameWithMixedCases.JsonOutput
 JsonInput.FieldNameWithMixedCases.ProtobufOutput
 JsonInput.FieldNameWithMixedCases.Validator
 JsonInput.OriginalProtoFieldName.JsonOutput
-JsonInput.OneofZeroBool.JsonOutput
-JsonInput.OneofZeroBool.ProtobufOutput
-JsonInput.OneofZeroDouble.JsonOutput
-JsonInput.OneofZeroDouble.ProtobufOutput
-JsonInput.OneofZeroEnum.JsonOutput
-JsonInput.OneofZeroEnum.ProtobufOutput
-JsonInput.OneofZeroFloat.JsonOutput
-JsonInput.OneofZeroFloat.ProtobufOutput
-JsonInput.OneofZeroUint64.JsonOutput
-JsonInput.OneofZeroUint64.ProtobufOutput
-ProtobufInput.OneofZeroBool.JsonOutput
-ProtobufInput.OneofZeroBool.ProtobufOutput
-ProtobufInput.OneofZeroDouble.JsonOutput
-ProtobufInput.OneofZeroDouble.ProtobufOutput
-ProtobufInput.OneofZeroEnum.JsonOutput
-ProtobufInput.OneofZeroEnum.ProtobufOutput
-ProtobufInput.OneofZeroFloat.JsonOutput
-ProtobufInput.OneofZeroFloat.ProtobufOutput
-ProtobufInput.OneofZeroUint64.JsonOutput
-ProtobufInput.OneofZeroUint64.ProtobufOutput