Description:
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If an exception is thrown from a __destruct in any object that has a 
cyclic references this results in an Exception without a stack frame.
This makes __destruct quiet unusable because this error is hard to debug 
large applications and cyclic references are quite common in OO.

Reproduce code:
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$ php -r 'class foo { public function __destruct() { throw new Exception("bar"); }} $f = new foo; $f2 = new foo; $f->foo = $f2; $f2->foo = $f; '


Actual result:
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PHP Fatal error:  Exception thrown without a stack frame in Unknown on 
line 0

Fatal error: Exception thrown without a stack frame in Unknown on line 0