Moving Wait() to XObject base.

src/xenia/kernel/objects/xevent.h

@@ -31,8 +31,7 @@ public:
   int32_t Reset();
   void Clear();
 
-  virtual X_STATUS Wait(uint32_t wait_reason, uint32_t processor_mode,
-                        uint32_t alertable, uint64_t* opt_timeout);
+  virtual void* GetWaitHandle() { return handle_; }
 
 private:
   HANDLE handle_;