Added a very complicated AsyncIterableReader class.

The class was already implemented in
"https://deno.land/std@0.144.0/streams/conversion.ts".  So, I litterally
lost 1 day of work!  I hate myself.

vendor/deno.land/std@0.188.0/bytes/concat.ts

@@ -0,0 +1,26 @@
+// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
+// This module is browser compatible.
+
+/** Concatenate the given arrays into a new Uint8Array.
+ *
+ * ```ts
+ * import { concat } from "https://deno.land/std@$STD_VERSION/bytes/concat.ts";
+ * const a = new Uint8Array([0, 1, 2]);
+ * const b = new Uint8Array([3, 4, 5]);
+ * console.log(concat(a, b)); // [0, 1, 2, 3, 4, 5]
+ */
+export function concat(...buf: Uint8Array[]): Uint8Array {
+  let length = 0;
+  for (const b of buf) {
+    length += b.length;
+  }
+
+  const output = new Uint8Array(length);
+  let index = 0;
+  for (const b of buf) {
+    output.set(b, index);
+    index += b.length;
+  }
+
+  return output;
+}