fix: add properties and methods to go wasm middleware, accessed via reflection

src/go_wasm.ts

@@ -82,6 +82,7 @@ export default class Go {
   private exited = false;
   private _resolveCallbackPromise?: () => void;
   importObject: ImportObject;
+  private _pendingEvent?: any;
 
   constructor() {
     this._callbackTimeouts = new Map();
@@ -437,6 +438,16 @@ export default class Go {
     }
     this._inst.exports.resume();
   }
+  _makeFuncWrapper(id) {
+    const go = this;
+    return function () {
+      const event = { id: id, this: this, args: arguments };
+      go._pendingEvent = event;
+      go._resume();
+      // @ts-ignore
+      return event.result;
+    };
+  }
 }
 
 if (