reorg: move JS ops implementations to cli/js/ops/, part 3 (#4302)

Following JS ops were moved to separate files in cli/js/ops directory:
- net
- tls
- fs

cli/js/link.ts

@@ -1,20 +0,0 @@
-// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
-import { sendSync, sendAsync } from "./ops/dispatch_json.ts";
-
-/** Creates `newname` as a hard link to `oldname`.
- *
- *       Deno.linkSync("old/name", "new/name");
- *
- * Requires `allow-read` and `allow-write` permissions. */
-export function linkSync(oldname: string, newname: string): void {
-  sendSync("op_link", { oldname, newname });
-}
-
-/** Creates `newname` as a hard link to `oldname`.
- *
- *       await Deno.link("old/name", "new/name");
- *
- * Requires `allow-read` and `allow-write` permissions. */
-export async function link(oldname: string, newname: string): Promise<void> {
-  await sendAsync("op_link", { oldname, newname });
-}