Known regression: top-level assignments with value's on RHS have unnecessary instrumentation

[arjunguha]

No description provided.

[rachitnigam]

Doesn't seem to happen for this file:

var x = 1;
var y = 2;
var z = foo();

==>

var $__T = stopify;
var $__R = $__T.newRTS("lazy");
var $S = stopify.init($__R);
var captureCC = $__R.captureCC.bind($__R);
var suspendCC = $__R.suspendCC;


function $top() {
  var target = null;
  $__R.remainingStack--;

  if (!$__R.mode) {
    const $frame = $__R.stack.pop();
    target = $frame.index;
    [foo, x, y, z] = $frame.locals;
  }

  function captureLocals(frame) {
    frame.locals = [foo, x, y, z];
  }

  var restoreNextFrame = () => {
    return $top.call(this);
  };

  var foo, x, y, z;

  if ($__R.mode) {
    x = 1;
    y = 2;
  }

  try {
    if ($__R.mode) {
      z = foo();
    } else if (target === 4) z = $__R.stack[$__R.stack.length - 1].f();
  } catch (exn1) {
    if (exn1 instanceof $__T.Capture) {
      exn1.stack.push({
        kind: "rest",
        f: restoreNextFrame,
        index: 4
      });
      captureLocals(exn1.stack[exn1.stack.length - 1]);
    }

    throw exn1;
  }

  $__R.remainingStack++;
}

$__R.runtime($top, result => {
  $S.onEnd(result);
});

Can you provide a test case with expected/actual output?