Add winptyCompat addon typings

fixtures/typings-test/typings-test.ts

@@ -41,6 +41,7 @@ namespace static_methods {
     Terminal.loadAddon('fullscreen');
     Terminal.loadAddon('search');
     Terminal.loadAddon('terminado');
+    Terminal.loadAddon('winptyCompat');
   }
 }
 

typings/xterm.d.ts

@@ -513,6 +513,6 @@ declare module 'xterm' {
      * available to all newly created Terminals.
      * @param addon The addon to load.
      */
-    static loadAddon(addon: 'attach' | 'fit' | 'fullscreen' | 'search' | 'terminado'): void;
+    static loadAddon(addon: 'attach' | 'fit' | 'fullscreen' | 'search' | 'terminado' | 'winptyCompat'): void;
   }
 }