unchecked pemalloc() return values

I fixed http://bugs.php.net/bug.php?id=32974 this morning, which was the result of 3 things going wrong at once. One of the problems was that the zend_llist functions don't check the return value from pemalloc(). With this particular bug, malloc() would fail, even though it was not a low memory condition, and that would cause a segv when populating the NULL element. I suspect we have a whole bunch of places where we don't check pemalloc() return values; the question is, are we concerned enough about them to add in a NULL check and raise an E_ERROR? --Wez.