Squeeze utf-8 characters in half their space

squeeze.js

let squeeze = s => s.replace(/../g,c=>String.fromCharCode(c[a='charCodeAt']()|c[a](1)<<7));
let unsqueeze = s => s.replace(/./g,c=>String.fromCharCode((c=c.charCodeAt())&127,c>>7));

console.log(unsqueeze("㟦ᑲᝣ㓷㩤㹨㒽Ჽ㒻ᚭᒻ᝸㓦㙬㋒㩣ᨨᠰ㒫ᢪᠰ⦫㨨ᔩᠳᘰᠴᘰᠵ᤬ᠰᶩ") === 
    "for(c.width|=i=9;i--;)x.fillRect(400+i*100+S(t)*300,400,50,200);");

console.log(squeeze("for(c.width|=i=9;i--;)x.fillRect(400+i*100+S(t)*300,400,50,200);") ===
    "㟦ᑲᝣ㓷㩤㹨㒽Ჽ㒻ᚭᒻ᝸㓦㙬㋒㩣ᨨᠰ㒫ᢪᠰ⦫㨨ᔩᠳᘰᠴᘰᠵ᤬ᠰᶩ");

console.log("㟦ᑲᝣ㓷㩤㹨㒽Ჽ㒻ᚭᒻ᝸㓦㙬㋒㩣ᨨᠰ㒫ᢪᠰ⦫㨨ᔩᠳᘰᠴᘰᠵ᤬ᠰᶩ".length === 32);
console.log("for(c.width|=i=9;i--;)x.fillRect(400+i*100+S(t)*300,400,50,200);".length === 64);

// codegolf example
eval("㟦ᑲᝣ㓷㩤㹨㒽Ჽ㒻ᚭᒻ᝸㓦㙬㋒㩣ᨨᠰ㒫ᢪᠰ⦫㨨ᔩᠳᘰᠴᘰᠵ᤬ᠰᶩ".replace(/./g,c=>String.fromCharCode((c=c.charCodeAt())&127,c>>7)))
eval([..."㟦ᑲᝣ㓷㩤㹨㒽Ჽ㒻ᚭᒻ᝸㓦㙬㋒㩣ᨨᠰ㒫ᢪᠰ⦫㨨ᔩᠳᘰᠴᘰᠵ᤬ᠰᶩ"].map(c=>String.fromCharCode((c=c.charCodeAt())&127,c>>7)).join``)
eval([].map.call("㟦ᑲᝣ㓷㩤㹨㒽Ჽ㒻ᚭᒻ᝸㓦㙬㋒㩣ᨨᠰ㒫ᢪᠰ⦫㨨ᔩᠳᘰᠴᘰᠵ᤬ᠰᶩ",c=>String.fromCharCode((c=c.charCodeAt())&127,c>>7)).join``)
eval([..." 㟦ᑲᝣ㓷㩤㹨㒽Ჽ㒻ᚭᒻ᝸㓦㙬㋒㩣ᨨᠰ㒫ᢪᠰ⦫㨨ᔩᠳᘰᠴᘰᠵ᤬ᠰᶩ"].reduce((a,c)=>a+=String.fromCharCode((c=c.charCodeAt())&127,c>>7)))