=== tests/cases/compiler/functionOverloads13.ts ===
function foo(bar:number):string;
>foo : { (bar: number): string; (bar: number): number; }
>bar : number

function foo(bar:number):number;
>foo : { (bar: number): string; (bar: number): number; }
>bar : number

function foo(bar?:number):any { return "" }
>foo : { (bar: number): string; (bar: number): number; }
>bar : number
>"" : string