Fix typecheck

Author: mjackson

demos/unpkg/global.d.ts

@@ -0,0 +1,6 @@
+// See https://github.com/DefinitelyTyped/DefinitelyTyped/discussions/62651
+
+interface ReadableStream<R = any> {
+  values(options?: { preventCancel?: boolean }): AsyncIterableIterator<R>
+  [Symbol.asyncIterator](): AsyncIterableIterator<R>
+}