Fix run line for windows

Author: maximdimakov

sycl/test/regression/bit_cast_win.cpp

@@ -1,4 +1,4 @@
-// RUN: %clangxx -fsycl -fsycl-host-compiler=cl -fsycl-host-compiler-options='-std=c++17' %s -o %t.out
+// RUN: %clangxx -fsycl -fsycl-host-compiler=cl -fsycl-host-compiler-options='/std:c++17' %s -o %t.out
 // UNSUPPORTED: linux
 
 #include "bit_cast.hpp"