代码如下，已经注册了错误处理函数register_shutdown_function都没有执行，很奇怪

    error_reporting(-1);
    ini_set('display_errors', 1);

    set_error_handler(function(){
        echo "error handler execute";
    }, E_ALL);

    set_exception_handler(function(){
        echo "exception handler execute";
    });

    register_shutdown_function(function(){
        echo "shutdown function execute";
    });

    try{
        0$a;
    }catch(exception $e){
        echo "catch exception";
    }finally{
        echo "finally ";
    }

执行结果:

Parse error: syntax error, unexpected '$a' (T_VARIABLE) in C:\Users\mao\Documents\php\index.php on line 18

PHP Parse error:  syntax error, unexpected '$a' (T_VARIABLE) in C:\Users\mao\Documents\php\index.php on line 18
[Finished in 0.1s]

0$a是故意写的，为什么异常都没有被处理呢？