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/last_index_of_needle.ts

@@ -0,0 +1,49 @@
+// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
+// This module is browser compatible.
+
+/** Returns the index of the last occurrence of the needle array in the source
+ * array, or -1 if it is not present.
+ *
+ * A start index can be specified as the third argument that begins the search
+ * at that given index. The start index defaults to the end of the array.
+ *
+ * The complexity of this function is O(source.lenth * needle.length).
+ *
+ * ```ts
+ * import { lastIndexOfNeedle } from "https://deno.land/std@$STD_VERSION/bytes/last_index_of_needle.ts";
+ * const source = new Uint8Array([0, 1, 2, 1, 2, 1, 2, 3]);
+ * const needle = new Uint8Array([1, 2]);
+ * console.log(lastIndexOfNeedle(source, needle)); // 5
+ * console.log(lastIndexOfNeedle(source, needle, 4)); // 3
+ * ```
+ */
+export function lastIndexOfNeedle(
+  source: Uint8Array,
+  needle: Uint8Array,
+  start = source.length - 1,
+): number {
+  if (start < 0) {
+    return -1;
+  }
+  if (start >= source.length) {
+    start = source.length - 1;
+  }
+  const e = needle[needle.length - 1];
+  for (let i = start; i >= 0; i--) {
+    if (source[i] !== e) continue;
+    const pin = i;
+    let matched = 1;
+    let j = i;
+    while (matched < needle.length) {
+      j--;
+      if (source[j] !== needle[needle.length - 1 - (pin - j)]) {
+        break;
+      }
+      matched++;
+    }
+    if (matched === needle.length) {
+      return pin - needle.length + 1;
+    }
+  }
+  return -1;
+}