Allow URL class object as an argument for fetch() (#1696)

* allow to fetch URL

* address comments

@types/index.d.ts

@@ -147,7 +147,7 @@ export type RequestRedirect = 'error' | 'follow' | 'manual';
 export type ReferrerPolicy = '' | 'no-referrer' | 'no-referrer-when-downgrade' | 'same-origin' | 'origin' | 'strict-origin' | 'origin-when-cross-origin' | 'strict-origin-when-cross-origin' | 'unsafe-url';
 export type RequestInfo = string | Request;
 export class Request extends BodyMixin {
-	constructor(input: RequestInfo, init?: RequestInit);
+	constructor(input: RequestInfo | URL, init?: RequestInit);
 
 	/**
 	 * Returns a Headers object consisting of the headers associated with request. Note that headers added in the network layer by the user agent will not be accounted for in this object, e.g., the "Host" header.
@@ -216,4 +216,4 @@ export class AbortError extends Error {
 }
 
 export function isRedirect(code: number): boolean;
-export default function fetch(url: RequestInfo, init?: RequestInit): Promise<Response>;
+export default function fetch(url: RequestInfo | URL, init?: RequestInit): Promise<Response>;

@types/index.test-d.ts

@@ -7,6 +7,7 @@ import * as _fetch from '.';
 
 async function run() {
 	const getResponse = await fetch('https://bigfile.com/test.zip');
+	await fetch(new URL('https://bigfile.com/test.zip'));
 	expectType<boolean>(getResponse.ok);
 	expectType<number>(getResponse.size);
 	expectType<number>(getResponse.status);
@@ -36,6 +37,7 @@ async function run() {
 	// Post
 	try {
 		const request = new Request('http://byjka.com/buka');
+		new Request(new URL('http://byjka.com/buka'));
 		expectType<string>(request.url);
 		expectType<Headers>(request.headers);