[]版本1.7.14beta , tsconfig.json里 target设置为es6， 项目发布时会报错，

移植代码， 因为用了get，set函数， 子类又有重写get，set 的需求，子类的get，set 又无法调用父类的get，set， 所以用了es6， 发现发布的项目的时候会报错，


Files\LayaAirIDE\resources\app\node_modules\uglify-js\lib\parse.js:204
throw new JS_Parse_Error(message, line, col, pos);
^
Error
at new JS_Parse_Error (E:\Program Files\LayaAirIDE\resources\app\node_modules\uglify-js\lib\parse.js:196:18)
at js_error (E:\Program Files\LayaAirIDE\resources\app\node_modules\uglify-js\lib\parse.js:204:11)
at croak (E:\Program Files\LayaAirIDE\resources\app\node_modules\uglify-js\lib\parse.js:663:9)
at token_error (E:\Program Files\LayaAirIDE\resources\app\node_modules\uglify-js\lib\parse.js:671:9)
at unexpected (E:\Program Files\LayaAirIDE\resources\app\node_modules\uglify-js\lib\parse.js:677:9)
at semicolon (E:\Program Files\LayaAirIDE\resources\app\node_modules\uglify-js\lib\parse.js:697:43)
at simple_statement (E:\Program Files\LayaAirIDE\resources\app\node_modules\uglify-js\lib\parse.js:871:73)
at E:\Program Files\LayaAirIDE\resources\app\node_