wrong target body for values used in multiple optimized functions

[NTillmann]

Prepacking this...

(function () {
  function outer(cond) {
    if (cond) {
      var value = 42;
      function inner1() { return value; }
      function inner2() { return value; }
      __optimize(inner1);
      __optimize(inner2);
      return [inner1, inner2];
    }
  }
  global.outer = outer;
  __optimize(outer);
})();

produces the following.

(function () {
  var _$0 = this;

  var _1 = function (cond) {
    var _6 = function () {
      return _8;
    };

    var _7 = function () {
      return _8;
    };

    return cond ? [_6, _7] : void 0;
  };

  var _8 = cond ? 42 : void 0;

  _$0.outer = _1;
}).call(this);

Note that _8 is defined in the global code, but refers to cond which is only defined in the outer function. The issue stems for various problems in _getTarget when it comes to optimized functions (some TODOs are present, some more things are implicitly wrong).