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/ops/fs/realpath.ts

@@ -0,0 +1,18 @@
+// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+import { sendSync, sendAsync } from "../dispatch_json.ts";
+
+/** Returns absolute normalized path with symbolic links resolved synchronously.
+ *
+ *       const realPath = Deno.realpathSync("./some/path");
+ */
+export function realpathSync(path: string): string {
+  return sendSync("op_realpath", { path });
+}
+
+/** Returns absolute normalized path with symbolic links resolved.
+ *
+ *       const realPath = await Deno.realpath("./some/path");
+ */
+export async function realpath(path: string): Promise<string> {
+  return await sendAsync("op_realpath", { path });
+}