=== tests/cases/compiler/functionOverloads28.ts ===
function foo():string;
>foo : { (): string; (bar: string): number; }

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

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

var t:any; var x = foo(t);
>t : any
>x : number
>foo(t) : number
>foo : { (): string; (bar: string): number; }
>t : any