Fix thread handles

src/windows-emulator/process_context.hpp

@@ -347,7 +347,7 @@ class moved_marker
     bool was_moved_{false};
 };
 
-class emulator_thread : ref_counted_object
+class emulator_thread : public ref_counted_object
 {
   public:
     emulator_thread(x64_emulator& emu)

src/windows-emulator/syscalls.cpp

@@ -3519,10 +3519,11 @@ namespace
         }
 
         bool return_next_thread = thread_handle == NULL_HANDLE;
-        for (const auto& t : c.proc.threads)
+        for (auto& t : c.proc.threads)
         {
             if (return_next_thread && !t.second.is_terminated())
             {
+                ++t.second.ref_count;
                 new_thread_handle.write(c.proc.threads.make_handle(t.first));
                 return STATUS_SUCCESS;
             }