refactor: move code from fs.rs into ops/fs.rs (#4428)

This a complex boring PR that shifts around code (primarily) in cli/fs.rs and
cli/ops/fs.rs. The gain of this refactoring is to ease the way for #4188 and
#4017, and also to avoid some future development pain.

Mostly there is no change in functionality. Except:
* squashed bugs where op_utime and op_chown weren't using `resolve_from_cwd`
* eliminated the use of the external `remove_dir_all` crate.
* op_chmod now only queries metadata to verify file/dir exists on Windows (it
  will already fail on Unix if it doesn't)
* op_chown now verifies the file/dir's existence on Windows like chmod does.

cli/js/lib.deno.ns.d.ts

@@ -1291,25 +1291,25 @@ declare namespace Deno {
 
   // @url js/link.d.ts
 
-  /** Creates `newname` as a hard link to `oldname`.
+  /** Creates `newpath` as a hard link to `oldpath`.
    *
    *       Deno.linkSync("old/name", "new/name");
    *
    * Requires `allow-read` and `allow-write` permissions. */
-  export function linkSync(oldname: string, newname: string): void;
+  export function linkSync(oldpath: string, newpath: string): void;
 
-  /** Creates `newname` as a hard link to `oldname`.
+  /** Creates `newpath` as a hard link to `oldpath`.
    *
    *       await Deno.link("old/name", "new/name");
    *
    * Requires `allow-read` and `allow-write` permissions. */
-  export function link(oldname: string, newname: string): Promise<void>;
+  export function link(oldpath: string, newpath: string): Promise<void>;
 
   // @url js/symlink.d.ts
 
   /** **UNSTABLE**: `type` argument type may be changed to `"dir" | "file"`.
    *
-   * Creates `newname` as a symbolic link to `oldname`. The type argument can be
+   * Creates `newpath` as a symbolic link to `oldpath`. The type argument can be
    * set to `dir` or `file`. Is only available on Windows and ignored on other
    * platforms.
    *
@@ -1317,14 +1317,14 @@ declare namespace Deno {
    *
    * Requires `allow-read` and `allow-write` permissions. */
   export function symlinkSync(
-    oldname: string,
-    newname: string,
+    oldpath: string,
+    newpath: string,
     type?: string
   ): void;
 
   /** **UNSTABLE**: `type` argument may be changed to "dir" | "file"
    *
-   * Creates `newname` as a symbolic link to `oldname`. The type argument can be
+   * Creates `newpath` as a symbolic link to `oldpath`. The type argument can be
    * set to `dir` or `file`. Is only available on Windows and ignored on other
    * platforms.
    *
@@ -1332,8 +1332,8 @@ declare namespace Deno {
    *
    * Requires `allow-read` and `allow-write` permissions. */
   export function symlink(
-    oldname: string,
-    newname: string,
+    oldpath: string,
+    newpath: string,
     type?: string
   ): Promise<void>;
 

cli/js/ops/fs/link.ts

@@ -1,10 +1,10 @@
 // Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
 import { sendSync, sendAsync } from "../dispatch_json.ts";
 
-export function linkSync(oldname: string, newname: string): void {
-  sendSync("op_link", { oldname, newname });
+export function linkSync(oldpath: string, newpath: string): void {
+  sendSync("op_link", { oldpath, newpath });
 }
 
-export async function link(oldname: string, newname: string): Promise<void> {
-  await sendAsync("op_link", { oldname, newname });
+export async function link(oldpath: string, newpath: string): Promise<void> {
+  await sendAsync("op_link", { oldpath, newpath });
 }

cli/js/ops/fs/symlink.ts

@@ -4,23 +4,23 @@ import * as util from "../../util.ts";
 import { build } from "../../build.ts";
 
 export function symlinkSync(
-  oldname: string,
-  newname: string,
+  oldpath: string,
+  newpath: string,
   type?: string
 ): void {
   if (build.os === "win" && type) {
     return util.notImplemented();
   }
-  sendSync("op_symlink", { oldname, newname });
+  sendSync("op_symlink", { oldpath, newpath });
 }
 
 export async function symlink(
-  oldname: string,
-  newname: string,
+  oldpath: string,
+  newpath: string,
   type?: string
 ): Promise<void> {
   if (build.os === "win" && type) {
     return util.notImplemented();
   }
-  await sendAsync("op_symlink", { oldname, newname });
+  await sendAsync("op_symlink", { oldpath, newpath });
 }