BREAKING(std): reorganization (#5087)

* Prepend underscores to private modules
* Remove collectUint8Arrays() It would be a misuse of Deno.iter()'s result.
* Move std/_util/async.ts to std/async
* Move std/util/sha*.ts to std/hash

std/fs/utils.ts

@@ -1,45 +0,0 @@
-import * as path from "../path/mod.ts";
-
-/**
- * Test whether or not `dest` is a sub-directory of `src`
- * @param src src file path
- * @param dest dest file path
- * @param sep path separator
- */
-export function isSubdir(
-  src: string,
-  dest: string,
-  sep: string = path.sep
-): boolean {
-  if (src === dest) {
-    return false;
-  }
-  const srcArray = src.split(sep);
-  const destArray = dest.split(sep);
-  // see: https://github.com/Microsoft/TypeScript/issues/30821
-  return srcArray.reduce(
-    // @ts-ignore
-    (acc: true, current: string, i: number): boolean => {
-      return acc && destArray[i] === current;
-    },
-    true
-  );
-}
-
-export type PathType = "file" | "dir" | "symlink";
-
-/**
- * Get a human readable file type string.
- *
- * @param fileInfo A FileInfo describes a file and is returned by `stat`,
- *                 `lstat`
- */
-export function getFileInfoType(fileInfo: Deno.FileInfo): PathType | undefined {
-  return fileInfo.isFile
-    ? "file"
-    : fileInfo.isDirectory
-    ? "dir"
-    : fileInfo.isSymlink
-    ? "symlink"
-    : undefined;
-}