text: //// [forOfStringConstituents.ts]
  interface A { x: 0; y: C[]; }
  interface B { x: 1; y: CD[]; }
  interface C { x: 2; }
  interface D { x: 3; }
  type AB = A | B;
  type CD = C | D;
  declare let x: AB, y: CD;
  for (y of x.y);
  
  //// [forOfStringConstituents.js]
  for (var _i = 0, _a = x.y; _i < _a.length; _i++) {
      y = _a[_i];
      ;
  }
  