private void AddDeclaredNontypeMembers(DeclaredMembersAndInitializersBuilder builder, DiagnosticBag diagnostics)
        {
...
            static ArrayBuilder<FieldOrPropertyInitializer>? noteRecordParameters(RecordDeclarationSyntax syntax, DeclaredMembersAndInitializersBuilder builder, DiagnosticBag diagnostics)
            {
                var parameterList = syntax.ParameterList;
                if (parameterList is null)
                {
                    return null;
                }

                if (builder.RecordDeclarationWithParameters is null)
                {
                    builder.RecordDeclarationWithParameters = syntax;
                    // Keep track of which instance initializers we'll want to update when we synthesize record properties
                    builder.InstanceInitializersIndexForRecordDeclarationWithParameters = builder.InstanceInitializers.Count;
                    return ArrayBuilder<FieldOrPropertyInitializer>.GetInstance();
                }
                else
                {
                    diagnostics.Add(ErrorCode.ERR_MultipleRecordParameterLists, parameterList.Location);
                    return null;
                }
            }
        }