Unicode strings break playground

[bgoscinski]

Repro: https://reasonml.github.io/try/?reason=DYUwLgBAtgngymAThAvBA3gKwM4B8CyMEAMgJZhigQCCwwpA5gIZgD2ygvBuBQO7jgL4BuAFBDQkWAmRoJSIbgB8EAFLYAdJNIA7BqsQgADsCYBjEAAoARLXrM2iCwBoIF2+wsBKOYpXqkWnXqGJuYWhI7OAJqsAK72ngrKahraugZGpmZYeK6cPPxOWbjRmqTG7JoQgHwbgCG7vNh88d5qwKwMQA

[codekiln]

Updated link:

[chenglou]

Little Alligator now works correctly