fixed ~200 warnings for windows

minor build system changes (now cuda code in opencv_core is compiled using CUDA_ARCH* cmake variables)

modules/ts/src/ts_perf.cpp

@@ -985,6 +985,7 @@ TestBase::_declareHelper& TestBase::_declareHelper::tbb_threads(int n)
     if (n > 0)
         test->p_tbb_initializer=new tbb::task_scheduler_init(n);
 #endif
+	(void)n;
     return *this;
 }