PHP 7.3 trailing comma additions
-----
<?php

foo($a, $b, );
$foo->bar($a, $b, );
Foo::bar($a, $b, );
new Foo($a, $b, );
unset($a, $b, );
isset($a, $b, );
-----
!!php7
array(
    0: Stmt_Expression(
        expr: Expr_FuncCall(
            name: Name(
                parts: array(
                    0: foo
                )
            )
            args: array(
                0: Arg(
                    name: null
                    value: Expr_Variable(
                        name: a
                    )
                    byRef: false
                    unpack: false
                )
                1: Arg(
                    name: null
                    value: Expr_Variable(
                        name: b
                    )
                    byRef: false
                    unpack: false
                )
            )
        )
    )
    1: Stmt_Expression(
        expr: Expr_MethodCall(
            var: Expr_Variable(
                name: foo
            )
            name: Identifier(
                name: bar
            )
            args: array(
                0: Arg(
                    name: null
                    value: Expr_Variable(
                        name: a
                    )
                    byRef: false
                    unpack: false
                )
                1: Arg(
                    name: null
                    value: Expr_Variable(
                        name: b
                    )
                    byRef: false
                    unpack: false
                )
            )
        )
    )
    2: Stmt_Expression(
        expr: Expr_StaticCall(
            class: Name(
                parts: array(
                    0: Foo
                )
            )
            name: Identifier(
                name: bar
            )
            args: array(
                0: Arg(
                    name: null
                    value: Expr_Variable(
                        name: a
                    )
                    byRef: false
                    unpack: false
                )
                1: Arg(
                    name: null
                    value: Expr_Variable(
                        name: b
                    )
                    byRef: false
                    unpack: false
                )
            )
        )
    )
    3: Stmt_Expression(
        expr: Expr_New(
            class: Name(
                parts: array(
                    0: Foo
                )
            )
            args: array(
                0: Arg(
                    name: null
                    value: Expr_Variable(
                        name: a
                    )
                    byRef: false
                    unpack: false
                )
                1: Arg(
                    name: null
                    value: Expr_Variable(
                        name: b
                    )
                    byRef: false
                    unpack: false
                )
            )
        )
    )
    4: Stmt_Unset(
        vars: array(
            0: Expr_Variable(
                name: a
            )
            1: Expr_Variable(
                name: b
            )
        )
    )
    5: Stmt_Expression(
        expr: Expr_Isset(
            vars: array(
                0: Expr_Variable(
                    name: a
                )
                1: Expr_Variable(
                    name: b
                )
            )
        )
    )
)