stream: apply special logic in removeListener for readable.off()

We have special logic in removeListener() which must apply
to off() as well.

PR-URL: #29486
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

lib/_stream_readable.js

@@ -908,6 +908,7 @@ Readable.prototype.removeListener = function(ev, fn) {
 
   return res;
 };
+Readable.prototype.off = Readable.prototype.removeListener;
 
 Readable.prototype.removeAllListeners = function(ev) {
   const res = Stream.prototype.removeAllListeners.apply(this, arguments);

test/parallel/test-stream-readable-readable-then-resume.js

@@ -2,6 +2,7 @@
 
 const common = require('../common');
 const { Readable } = require('stream');
+const assert = require('assert');
 
 // This test verifies that a stream could be resumed after
 // removing the readable event in the same tick
@@ -24,6 +25,7 @@ function check(s) {
   const readableListener = common.mustNotCall();
   s.on('readable', readableListener);
   s.on('end', common.mustCall());
+  assert.strictEqual(s.removeListener, s.off);
   s.removeListener('readable', readableListener);
   s.resume();
 }