revert 'arm64 implementations of SDL_Swap16/32' for now (bug #5419)

include/SDL_endian.h

@@ -92,13 +92,6 @@ SDL_Swap16(Uint16 x)
   __asm__("rlwimi %0,%2,8,16,23": "=&r"(result):"0"(x >> 8), "r"(x));
     return (Uint16)result;
 }
-#elif defined(__GNUC__) && defined(__aarch64__)
-SDL_FORCE_INLINE Uint16
-SDL_Swap16(Uint16 x)
-{
-  __asm__("rev16 %1, %0" : "=r"(x) : "r"(x));
-  return x;
-}
 #elif defined(__GNUC__) && (defined(__M68000__) || defined(__M68020__)) && !defined(__mcoldfire__)
 SDL_FORCE_INLINE Uint16
 SDL_Swap16(Uint16 x)
@@ -145,13 +138,6 @@ SDL_Swap32(Uint32 x)
   __asm__("rlwimi %0,%2,24,0,7": "=&r"(result):"0"(result), "r"(x));
     return result;
 }
-#elif defined(__GNUC__) && defined(__aarch64__)
-SDL_FORCE_INLINE Uint32
-SDL_Swap32(Uint32 x)
-{
-  __asm__("rev %1, %0": "=r"(x):"r"(x));
-    return x;
-}
 #elif defined(__GNUC__) && (defined(__M68000__) || defined(__M68020__)) && !defined(__mcoldfire__)
 SDL_FORCE_INLINE Uint32
 SDL_Swap32(Uint32 x)