Merged PR 473808: Use arrow function to explicitly capture this

Otherwise when green calls our function back, 'this' does not point to the language server any more (it is undefined).
See https://stackoverflow.com/questions/20279484/how-to-access-the-correct-this-inside-a-callback

Related work items: #1823584

Author: dibarbet

src/lsptoolshost/roslynLanguageServer.ts

@@ -329,7 +329,7 @@ export class RoslynLanguageServer {
                 this._languageClient?.sendNotification("serviceBroker/connect", { pipeName: pipeName });
             } else {
                 // We'll subscribe if the process later launches, and call this function again to send the pipe name.
-                this.context.subscriptions.push(exports.serverProcessLoaded(this.sendOrSubscribeForServiceBrokerConnection));
+                this.context.subscriptions.push(exports.serverProcessLoaded(async() => this.sendOrSubscribeForServiceBrokerConnection()));
             }
         }
     }