Variadic functions
-----
<?php
function test($a, ... $b) {}
function test($a, &... $b) {}
function test($a, Type ... $b) {}
function test($a, Type &... $b) {}
-----
array(
    0: Stmt_Function(
        byRef: false
        name: test
        params: array(
            0: Param(
                type: null
                byRef: false
                variadic: false
                name: a
                default: null
            )
            1: Param(
                type: null
                byRef: false
                variadic: true
                name: b
                default: null
            )
        )
        returnType: null
        stmts: array(
        )
    )
    1: Stmt_Function(
        byRef: false
        name: test
        params: array(
            0: Param(
                type: null
                byRef: false
                variadic: false
                name: a
                default: null
            )
            1: Param(
                type: null
                byRef: true
                variadic: true
                name: b
                default: null
            )
        )
        returnType: null
        stmts: array(
        )
    )
    2: Stmt_Function(
        byRef: false
        name: test
        params: array(
            0: Param(
                type: null
                byRef: false
                variadic: false
                name: a
                default: null
            )
            1: Param(
                type: Name(
                    parts: array(
                        0: Type
                    )
                )
                byRef: false
                variadic: true
                name: b
                default: null
            )
        )
        returnType: null
        stmts: array(
        )
    )
    3: Stmt_Function(
        byRef: false
        name: test
        params: array(
            0: Param(
                type: null
                byRef: false
                variadic: false
                name: a
                default: null
            )
            1: Param(
                type: Name(
                    parts: array(
                        0: Type
                    )
                )
                byRef: true
                variadic: true
                name: b
                default: null
            )
        )
        returnType: null
        stmts: array(
        )
    )
)