Revert cl.hpp change since OpenCL on ARM64 is not needed

Author: weng271190436

inc/OpenCL/cl.hpp

@@ -202,7 +202,6 @@
 
 #include <utility>
 #include <limits>
-#include <atomic>
 
 #if !defined(__NO_STD_VECTOR)
 #include <vector>
@@ -215,11 +214,8 @@
 #if defined(linux) || defined(__APPLE__) || defined(__MACOSX)
 #include <alloca.h>
 
-#if defined(__i386__) || defined(__x86_64__) || defined(_M_IX86) || \
-    defined(_M_X64)
 #include <emmintrin.h>
 #include <xmmintrin.h>
-#endif
 #endif // linux
 
 #include <cstring>
@@ -1042,15 +1038,7 @@ namespace detail {
 #endif // !_WIN32
     }
 
-    inline void fence()
-    {
-#if defined(__i386__) || defined(__x86_64__) || defined(_M_IX86) || \
-    defined(_M_X64)
-        _mm_mfence();
-#else
-        std::atomic_thread_fence(std::memory_order_seq_cst);
-#endif
-    }
+    inline void fence() { _mm_mfence(); }
 }; // namespace detail