Fix for-of loop jsligo

In cases where for-of loop body has multiple statements, modifications made inside the loop body are not preserved

let out : int = 999;

let _test : (x:unit) => unit = () => {
  let x : list<int> = list([1,2,3]);
  let y : list<int> = list([]);
  for (const i of x) {
    let xx = 1;
    let xy = 1;
    let yy = 2;
    y = list([out,...y]);
    Test.log(y);
  };
  Test.log(y);
  Test.log("Here");
};

let test = _test();

output

[999]
[999]
[999]
[]
"Here"
Everything at the top-level was executed.
- test exited with value ().

• has a changelog entry