public void AddInstructions(LightCompiler compiler) {
                compiler.PushLabelBlock(LabelScopeKind.Block);

                var local = compiler.Locals.DefineLocal(_lastValue, compiler.Instructions.Count);
                var label = compiler.DefineLabel(_returnLabel);
                compiler.Compile(_body);
                compiler.Instructions.MarkLabel(label.GetLabel(compiler));
                compiler.Locals.UndefineLocal(local, compiler.Instructions.Count);

                compiler.PopLabelBlock(LabelScopeKind.Block);
            }