Conditional function definition
-----
<?php

if (true) {
    function A() {}
}
-----
array(
    0: Stmt_If(
        stmts: array(
            0: Stmt_Function(
                byRef: false
                params: array(
                )
                stmts: array(
                )
                name: A
            )
        )
        elseifs: array(
        )
        else: null
        cond: Expr_ConstFetch(
            name: Name(
                parts: array(
                    0: true
                )
            )
        )
    )
)