Description:
------------
Temporary variables of an aborted vm stack are never freed and thus leak...

Test script:
---------------
$gen = (function(){
    $tmp = 1;
    [$tmp] + yield; // temporary variable created, but never freed as it halts after yield
})();
$gen->valid(); // run until first yield

Expected result:
----------------
No memory leak

Actual result:
--------------
[Fri Jun 19 23:29:53 2015]  Script:  '/Users/Bob/Icicle/examples/repro2.php'
Zend/zend_vm_execute.h(35171) :  Freeing 0x103C5B480 (56 bytes), script=/Users/Bob/Icicle/examples/repro2.php
[Fri Jun 19 23:29:53 2015]  Script:  '/Users/Bob/Icicle/examples/repro2.php'
/Users/Bob/php-src-7.0x/Zend/zend_hash.c(128) :  Freeing 0x103C61B40 (264 bytes), script=/Users/Bob/Icicle/examples/repro2.php
=== Total 2 memory leaks detected ===