Description:
------------
When using generators with an anonymous function neither an error nor the expected 
result are shown.

Test script:
---------------
  foreach (function ()
  {

    for ($i = 1; $i <= 10; ++$i)
    {
      yield $i => $i;
    }

  } as $key => $value)
  {
    echo $key . ': ' . $value . '<br>';
  }

Expected result:
----------------
Either:

1: 1
2: 2
3: 3
4: 4
5: 5
6: 6
7: 7
8: 8
9: 9
10: 10

Or an error of some sort.

Actual result:
--------------
[neither result nor error]