Abstract condition on return returns self instead of actual return value

[calebmer]

This seems like a bug in simplification?

main(1);

// Expected: true
//   Actual: 1

Input

(function() {
  "use strict";

  function main(a1) {
    if (a1) {
      return true;
    }
    return false;
  }

  if (global.__optimize) __optimize(main);
  module.exports = main;
})();

Output

(function () {
  "use strict";

  var _2 = function (a1) {
    return a1;
  };

  module.exports = _2;
})();