Yep, on Unixen the translation of CRLF to LF when printing to the terminal (and from CR to CRLF when reading input from the terminal) is done in the kernel, it's called "line discipline".
spin='/-\|'
while true; do
i=$(( (i+1) % 4 ))
printf "\r${spin:$i:1} Working..."
sleep 0.1
done