Variable variable positions
-----
<?php
$$$x;
-----
!!positions
array(
    0: Stmt_Expression[2:1 - 2:5](
        expr: Expr_Variable[2:1 - 2:4](
            name: Expr_Variable[2:2 - 2:4](
                name: Expr_Variable[2:3 - 2:4](
                    name: x
                )
            )
        )
    )
)