stream: name anonymous function in _stream_writable.js

PR-URL: nodejs#21753
Refs: nodejs#8913
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Jon Moss <me@jonathanmoss.me>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

lib/_stream_writable.js

@@ -168,7 +168,7 @@ WritableState.prototype.getBuffer = function getBuffer() {
 };
 
 Object.defineProperty(WritableState.prototype, 'buffer', {
-  get: internalUtil.deprecate(function() {
+  get: internalUtil.deprecate(function writableStateBufferGetter() {
     return this.getBuffer();
   }, '_writableState.buffer is deprecated. Use _writableState.getBuffer ' +
      'instead.', 'DEP0003')