Function calls
-----
<?php

// function name variations
a();
$a();
${'a'}();
$$a();
$$$a();
$a['b']();
$a->b['c']();

// array dereferencing
a()['b'];
-----
array(
    0: Stmt_Expression(
        expr: Expr_FuncCall(
            name: Name(
                name: a
            )
            args: array(
            )
        )
        comments: array(
            0: // function name variations
        )
    )
    1: Stmt_Expression(
        expr: Expr_FuncCall(
            name: Expr_Variable(
                name: a
            )
            args: array(
            )
        )
    )
    2: Stmt_Expression(
        expr: Expr_FuncCall(
            name: Expr_Variable(
                name: Scalar_String(
                    value: a
                )
            )
            args: array(
            )
        )
    )
    3: Stmt_Expression(
        expr: Expr_FuncCall(
            name: Expr_Variable(
                name: Expr_Variable(
                    name: a
                )
            )
            args: array(
            )
        )
    )
    4: Stmt_Expression(
        expr: Expr_FuncCall(
            name: Expr_Variable(
                name: Expr_Variable(
                    name: Expr_Variable(
                        name: a
                    )
                )
            )
            args: array(
            )
        )
    )
    5: Stmt_Expression(
        expr: Expr_FuncCall(
            name: Expr_ArrayDimFetch(
                var: Expr_Variable(
                    name: a
                )
                dim: Scalar_String(
                    value: b
                )
            )
            args: array(
            )
        )
    )
    6: Stmt_Expression(
        expr: Expr_FuncCall(
            name: Expr_ArrayDimFetch(
                var: Expr_PropertyFetch(
                    var: Expr_Variable(
                        name: a
                    )
                    name: Identifier(
                        name: b
                    )
                )
                dim: Scalar_String(
                    value: c
                )
            )
            args: array(
            )
        )
    )
    7: Stmt_Expression(
        expr: Expr_ArrayDimFetch(
            var: Expr_FuncCall(
                name: Name(
                    name: a
                )
                args: array(
                )
            )
            dim: Scalar_String(
                value: b
            )
        )
        comments: array(
            0: // array dereferencing
        )
    )
)