reduced.js

function genT() {
  return function T() {
  }
}

function O() {
  this.fn = null;

  this.changes = 0;
}

O.prototype.outer = function outer(a) {
  return this.middle(a);
};

O.prototype.middle = function middle(a) {
  "use strict";
  this.inner(a);
  return arguments.length > 2 ? arguments[2] : void 0;
};

O.prototype.inner = function inner(a) {
  var r = new (genT())(this.spillT(), a.changes * 2);
};

// Just to force pushing T with PushArgument
O.prototype.spillT = function spillT() {
  debugger;
};

var o = new O();
o.outer(o);
o.outer(o);
%OptimizeFunctionOnNextCall(o.outer);
o.outer(o);
o.changes = true;
o.outer(o);