Reverse the order of letters encoded in UTF-8

I have a variable encoded in Arabic (UTF-8), but in reverse order:

y <- "سنوت"

      

        
        
        
      

    

The correct word should be:

     تونس    # Tunisia for curious

      

        
        
        
      

    

I am trying to change this word like this:

rawToChar(rev(charToRaw(y)))
[1] "\xaa؈نٳ\xd8"

      

        
        
        
      

    

but it doesn't work. Please note that this works fine with encoded ASCII characters:

y <- "ydutsga"
> rawToChar(rev(charToRaw(y)))
[1] "agstudy"