stream: make Symbol.asyncIterator support stable

PR-URL: #26989
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Masashi Hirano <shisama07@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>

doc/api/stream.md

@@ -1286,9 +1286,13 @@ myReader.on('readable', () => {
 ##### readable\[Symbol.asyncIterator\]()
 <!-- YAML
 added: v10.0.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/26989
+    description: Symbol.asyncIterator support is no longer experimental.
 -->
 
-> Stability: 1 - Experimental
+> Stability: 2 - Stable
 
 * Returns: {AsyncIterator} to fully consume the stream.
 

lib/_stream_readable.js

@@ -46,7 +46,6 @@ const {
   ERR_METHOD_NOT_IMPLEMENTED,
   ERR_STREAM_UNSHIFT_AFTER_END_EVENT
 } = require('internal/errors').codes;
-const { emitExperimentalWarning } = require('internal/util');
 
 // Lazy loaded to improve the startup performance.
 let StringDecoder;
@@ -1036,7 +1035,6 @@ Readable.prototype.wrap = function(stream) {
 };
 
 Readable.prototype[Symbol.asyncIterator] = function() {
-  emitExperimentalWarning('Readable[Symbol.asyncIterator]');
   if (createReadableStreamAsyncIterator === undefined) {
     createReadableStreamAsyncIterator =
       require('internal/streams/async_iterator');