Add a diagnostic.getServerPort analysis server request.

pkg/analysis_server/tool/spec/generated/java/types/RequestErrorCode.java

 /*
  * Copyright (c) 2015, the Dart project authors.
  *
  * Licensed under the Eclipse Public License v1.0 (the "License"); you may not use this file except
  * in compliance with the License. You may obtain a copy of the License at
  *
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Unless required by applicable law or agreed to in writing, software distributed under the License
  * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
@@ skipping 96 matching lines @@
    * is described in the message.
    */
   public static final String ORGANIZE_DIRECTIVES_ERROR = "ORGANIZE_DIRECTIVES_ERROR";
 
   /**
    * Another refactoring request was received during processing of this one.
    */
   public static final String REFACTORING_REQUEST_CANCELLED = "REFACTORING_REQUEST_CANCELLED";
 
   /**
+   * The server was unable to handle the request.
+   */
+  public static final String ERROR_HANDLING_REQUEST = "ERROR_HANDLING_REQUEST";
+
+  /**
    * The analysis server has already been started (and hence won't accept new connections).
    *
    * This error is included for future expansion; at present the analysis server can only speak to
    * one client at a time so this error will never occur.
    */
   public static final String SERVER_ALREADY_STARTED = "SERVER_ALREADY_STARTED";
 
   /**
    * An internal error occurred in the analysis server. Also see the server.error notification.
    */
@@ skipping 29 matching lines @@
   public static final String UNKNOWN_SOURCE = "UNKNOWN_SOURCE";
 
   /**
    * The analysis server was requested to perform an action which is not supported.
    *
    * This is a legacy error; it will be removed before the API reaches version 1.0.
    */
   public static final String UNSUPPORTED_FEATURE = "UNSUPPORTED_FEATURE";
 
 }