Add missing perMessageDeflate server option (#11380)

ws/ws-tests.ts

@@ -81,3 +81,17 @@ var WebSocketServer = WebSocket.Server;
         console.log(ws.protocol)
     })
 }
+
+{
+    new WebSocket.Server({ perMessageDeflate: false });
+    new WebSocket.Server({ perMessageDeflate: { } });
+    new WebSocket.Server({
+        perMessageDeflate: {
+            serverNoContextTakeover: true,
+            clientNoContextTakeover: true,
+            serverMaxWindowBits: 0,
+            clientMaxWindowBits: 0,
+            memLevel: 0
+        }
+    });
+}

ws/ws.d.ts

@@ -96,6 +96,14 @@ declare module "ws" {
             ciphers?: string;
             rejectUnauthorized?: boolean;
         }
+
+        export interface IPerMessageDeflateOptions {
+            serverNoContextTakeover?: boolean;
+            clientNoContextTakeover?: boolean;
+            serverMaxWindowBits?: number;
+            clientMaxWindowBits?: number;
+            memLevel?: number;
+        }
         
         export interface IServerOptions {
             host?: string;
@@ -107,6 +115,7 @@ declare module "ws" {
             noServer?: boolean;
             disableHixie?: boolean;
             clientTracking?: boolean;
+            perMessageDeflate?: boolean | IPerMessageDeflateOptions;
         }
 
         export class Server extends events.EventEmitter {