shuffle != hash is re-using variable x and crashing

[Le0Developer]

Describe the bug:

One of the shuffle variants (for shuffle != hash) is re-using the variables x, z and i.
If they are present before (very likely), it'll compile to invalid JS code.

Config and Small code sample

Code:

let x = -999;
let a = [1, 2, 3, 4, 5, 6];

Expected behavior

Should run.

Actual behavior

Uncaught SyntaxError: Identifier 'x' has already been declared when running.

let x = -999;
let a = [
    2,
    3,
    4,
    5,
    6,
    1
];
var __p_6792745382 = a;
for (var x = 16; x % 4 === 0; x++) {
    var z = 0;
    a = __p_6792745382 = __p_6792745382.concat(function () {
        z++;
        if (z === 1) {
            return [];
        }
        for (var i = 20; i; i--) {
            __p_6792745382.unshift(__p_6792745382.pop());
        }
        return [];
    }());
}
for (var __p_4040364912 = 13; __p_4040364912; __p_4040364912--) {
    __p_6792745382.unshift(__p_6792745382.pop());
}