Description:
------------
until 5.6.26, I can call a method for a object in the below form which the $value is a method in the class:

$objName->$arrName[$key]();

but from 7.0, I got error message like:

PHP Notice:  Array to string conversion in /home/xxx/test.php on line 12
PHP Notice:  Undefined property: TestClass::$Array in /home/xxx/test.php on line 12
PHP Fatal error:  Uncaught Error: Function name must be a string in /home/xxx/test.php:12
Stack trace:
#0 {main}
  thrown in /home/xxx/test.php on line 12

Test script:
---------------
<?php
class TestClass{
    function testFunc() {
        echo "a\n";
    }
}

$funcs = array( "a" => "testFunc");

$testObject = new TestClass();
$funcTag = "a";
$testObject->$funcs[$funcTag]();